diff --git a/packages/page-accounts/src/modals/Transfer.tsx b/packages/page-accounts/src/modals/Transfer.tsx
index 697d64e76d..c94ddf4576 100644
--- a/packages/page-accounts/src/modals/Transfer.tsx
+++ b/packages/page-accounts/src/modals/Transfer.tsx
@@ -12,7 +12,7 @@ import { checkAddress } from '@polkadot/phishing';
 import { InputAddress, InputBalance, MarkError, MarkWarning, Modal, Toggle, TxButton } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
 import { Available } from '@polkadot/react-query';
-import { BN_ZERO, isFunction } from '@polkadot/util';
+import { BN_HUNDRED, BN_ZERO, isFunction } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -65,7 +65,7 @@ function Transfer ({ className = '', onClose, recipientId: propRecipientId, send
             .transfer(toId, balances.availableBalance)
             .paymentInfo(fromId)
             .then(({ partialFee }): void => {
-              const adjFee = partialFee.muln(110).divn(100);
+              const adjFee = partialFee.muln(110).div(BN_HUNDRED);
               const maxTransfer = balances.availableBalance.sub(adjFee);
 
               setMaxTransfer(
diff --git a/packages/page-bounties/src/BountyInfos.tsx b/packages/page-bounties/src/BountyInfos.tsx
index f4686835f5..56b7664784 100644
--- a/packages/page-bounties/src/BountyInfos.tsx
+++ b/packages/page-bounties/src/BountyInfos.tsx
@@ -8,6 +8,7 @@ import BN from 'bn.js';
 import React from 'react';
 
 import { AddressSmall } from '@polkadot/react-components';
+import { BN_HUNDRED } from '@polkadot/util';
 
 import VotingSummary from './Voting/VotingSummary';
 import BountyInfo from './BountyInfo';
@@ -30,7 +31,7 @@ function BountyInfos ({ beneficiary, blocksUntilUpdate, proposals, status }: Pro
 
   const { bountyUpdatePeriod } = useBounties();
 
-  const blocksPercentageLeftToShowWarning = bountyUpdatePeriod?.muln(BLOCKS_PERCENTAGE_LEFT_TO_SHOW_WARNING).divn(100);
+  const blocksPercentageLeftToShowWarning = bountyUpdatePeriod?.muln(BLOCKS_PERCENTAGE_LEFT_TO_SHOW_WARNING).div(BN_HUNDRED);
   const blocksToShowWarning = blocksPercentageLeftToShowWarning ?? BLOCKS_LEFT_TO_SHOW_WARNING;
 
   return (
diff --git a/packages/page-bounties/src/helpers/permillOf.ts b/packages/page-bounties/src/helpers/permillOf.ts
index 8e5e276be2..ff1db95bf3 100644
--- a/packages/page-bounties/src/helpers/permillOf.ts
+++ b/packages/page-bounties/src/helpers/permillOf.ts
@@ -3,6 +3,8 @@
 
 import BN from 'bn.js';
 
+import { BN_MILLION } from '@polkadot/util';
+
 export function permillOf (value: BN, perMill: BN): BN {
-  return value.mul(perMill).div(new BN(1_000_000));
+  return value.mul(perMill).div(BN_MILLION);
 }
diff --git a/packages/page-calendar/src/useScheduled.ts b/packages/page-calendar/src/useScheduled.ts
index eccb8c13bb..b90d7a9d9c 100644
--- a/packages/page-calendar/src/useScheduled.ts
+++ b/packages/page-calendar/src/useScheduled.ts
@@ -81,7 +81,7 @@ function createDispatches (bestNumber: BlockNumber, blockTime: number, dispatche
 function createReferendums (bestNumber: BlockNumber, blockTime: number, referendums: DeriveReferendumExt[]): [EntryType, EntryInfo[]][] {
   return referendums.reduce((result: [EntryType, EntryInfo[]][], { index, status }): [EntryType, EntryInfo[]][] => {
     const enactBlocks = status.end.add(status.delay).sub(bestNumber);
-    const voteBlocks = status.end.sub(bestNumber).subn(1);
+    const voteBlocks = status.end.sub(bestNumber).isub(BN_ONE);
 
     result.push(['referendumVote', [{
       ...newDate(voteBlocks, blockTime),
@@ -110,7 +110,7 @@ function createStakingInfo (bestNumber: BlockNumber, blockTime: number, sessionI
       .filter(([, values]) => values.length)
       .map(([key]): EntryInfo => {
         const eraIndex = key.args[0];
-        const blockProgress = sessionInfo.activeEra.sub(eraIndex).subn(1).mul(sessionInfo.eraLength).add(sessionInfo.eraProgress);
+        const blockProgress = sessionInfo.activeEra.sub(eraIndex).isub(BN_ONE).imul(sessionInfo.eraLength).iadd(sessionInfo.eraProgress);
         const blocks = slashDuration.sub(blockProgress);
 
         return {
diff --git a/packages/page-contracts/src/Contracts/Call.tsx b/packages/page-contracts/src/Contracts/Call.tsx
index 02644f4bb4..e6a5ec36ca 100644
--- a/packages/page-contracts/src/Contracts/Call.tsx
+++ b/packages/page-contracts/src/Contracts/Call.tsx
@@ -13,7 +13,7 @@ import { ContractPromise } from '@polkadot/api-contract';
 import { Button, Dropdown, Expander, InputAddress, InputBalance, Modal, Toggle, TxButton } from '@polkadot/react-components';
 import { useAccountId, useDebounce, useFormField, useToggle } from '@polkadot/react-hooks';
 import { Available } from '@polkadot/react-query';
-import { BN_ZERO } from '@polkadot/util';
+import { BN_ONE, BN_ZERO } from '@polkadot/util';
 
 import { InputMegaGas, Params } from '../shared';
 import { useTranslation } from '../translate';
@@ -30,7 +30,7 @@ interface Props {
   onClose: () => void;
 }
 
-const MAX_CALL_WEIGHT = new BN(5_000_000_000_000).subn(1);
+const MAX_CALL_WEIGHT = new BN(5_000_000_000_000).isub(BN_ONE);
 
 function Call ({ className = '', contract, messageIndex, onCallResult, onChangeMessage, onClose }: Props): React.ReactElement<Props> | null {
   const { t } = useTranslation();
diff --git a/packages/page-contracts/src/shared/InputMegaGas.tsx b/packages/page-contracts/src/shared/InputMegaGas.tsx
index 318d916cd0..a5059c2c86 100644
--- a/packages/page-contracts/src/shared/InputMegaGas.tsx
+++ b/packages/page-contracts/src/shared/InputMegaGas.tsx
@@ -8,7 +8,7 @@ import React, { useEffect, useMemo, useState } from 'react';
 import styled from 'styled-components';
 
 import { InputNumber, Toggle } from '@polkadot/react-components';
-import { BN_ZERO } from '@polkadot/util';
+import { BN_MILLION, BN_ONE, BN_ZERO } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -20,15 +20,13 @@ interface Props {
   weight: UseWeight;
 }
 
-const MEGA = new BN(1_000_000);
-
 function InputMegaGas ({ className, estimatedWeight, help, isCall, weight: { executionTime, isValid, megaGas, percentage, setIsEmpty, setMegaGas } }: Props): React.ReactElement<Props> {
   const { t } = useTranslation();
   const [withEstimate, setWithEstimate] = useState(true);
 
   const estimatedMg = useMemo(
     () => estimatedWeight
-      ? estimatedWeight.div(MEGA).iaddn(1)
+      ? estimatedWeight.div(BN_MILLION).iadd(BN_ONE)
       : null,
     [estimatedWeight]
   );
diff --git a/packages/page-contracts/src/useWeight.ts b/packages/page-contracts/src/useWeight.ts
index b07a62a93f..e4637f4895 100644
--- a/packages/page-contracts/src/useWeight.ts
+++ b/packages/page-contracts/src/useWeight.ts
@@ -8,9 +8,7 @@ import BN from 'bn.js';
 import { useCallback, useMemo, useState } from 'react';
 
 import { useApi, useBlockTime } from '@polkadot/react-hooks';
-import { BN_TEN, BN_ZERO } from '@polkadot/util';
-
-const BN_MILLION = new BN(1_000_000);
+import { BN_MILLION, BN_TEN, BN_ZERO } from '@polkadot/util';
 
 export default function useWeight (): UseWeight {
   const { api } = useApi();
diff --git a/packages/page-democracy/src/Overview/Referendum.tsx b/packages/page-democracy/src/Overview/Referendum.tsx
index e04e57ed17..a173560d0c 100644
--- a/packages/page-democracy/src/Overview/Referendum.tsx
+++ b/packages/page-democracy/src/Overview/Referendum.tsx
@@ -11,7 +11,7 @@ import styled from 'styled-components';
 import { Badge, Button, Icon, LinkExternal } from '@polkadot/react-components';
 import { useAccounts, useApi, useCall } from '@polkadot/react-hooks';
 import { BlockToTime } from '@polkadot/react-query';
-import { formatNumber, isBoolean } from '@polkadot/util';
+import { BN_ONE, formatNumber, isBoolean } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 import useChangeCalc from '../useChangeCalc';
@@ -82,7 +82,7 @@ function Referendum ({ className = '', value: { allAye, allNay, image, imageHash
   }
 
   const enactBlock = status.end.add(status.delay);
-  const remainBlock = status.end.sub(bestNumber).subn(1);
+  const remainBlock = status.end.sub(bestNumber).isub(BN_ONE);
 
   return (
     <tr className={className}>
diff --git a/packages/page-democracy/src/Overview/ReferendumVotes.tsx b/packages/page-democracy/src/Overview/ReferendumVotes.tsx
index 86ff555159..17f24133a1 100644
--- a/packages/page-democracy/src/Overview/ReferendumVotes.tsx
+++ b/packages/page-democracy/src/Overview/ReferendumVotes.tsx
@@ -8,7 +8,7 @@ import React, { useMemo } from 'react';
 
 import { Expander } from '@polkadot/react-components';
 import { FormatBalance } from '@polkadot/react-query';
-import { formatNumber } from '@polkadot/util';
+import { BN_TEN, formatNumber } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 import ReferendumVote from './ReferendumVote';
@@ -30,8 +30,8 @@ function ReferendumVotes ({ change, className, count, isAye, isWinning, total, v
 
   const sorted = useMemo(
     () => votes.sort((a, b) => {
-      const ta = a.balance.muln(LOCKS[a.vote.conviction.toNumber()]).divn(10);
-      const tb = b.balance.muln(LOCKS[b.vote.conviction.toNumber()]).divn(10);
+      const ta = a.balance.muln(LOCKS[a.vote.conviction.toNumber()]).div(BN_TEN);
+      const tb = b.balance.muln(LOCKS[b.vote.conviction.toNumber()]).div(BN_TEN);
 
       return tb.cmp(ta);
     }),
diff --git a/packages/page-democracy/src/Overview/Summary.tsx b/packages/page-democracy/src/Overview/Summary.tsx
index 7458eb1334..7ddab1eaac 100644
--- a/packages/page-democracy/src/Overview/Summary.tsx
+++ b/packages/page-democracy/src/Overview/Summary.tsx
@@ -6,7 +6,7 @@ import React from 'react';
 
 import { CardSummary, SummaryBox } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
-import { formatNumber } from '@polkadot/util';
+import { BN_ONE, formatNumber } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -46,7 +46,7 @@ function Summary ({ referendumCount }: Props): React.ReactElement<Props> {
             label={t<string>('launch period')}
             progress={{
               total: api.consts.democracy.launchPeriod,
-              value: bestNumber.mod(api.consts.democracy.launchPeriod).addn(1),
+              value: bestNumber.mod(api.consts.democracy.launchPeriod).iadd(BN_ONE),
               withTime: true
             }}
           />
diff --git a/packages/page-explorer/src/SummarySession.tsx b/packages/page-explorer/src/SummarySession.tsx
index 83b5cbd14d..a753e8ad1e 100644
--- a/packages/page-explorer/src/SummarySession.tsx
+++ b/packages/page-explorer/src/SummarySession.tsx
@@ -9,7 +9,7 @@ import React from 'react';
 import { CardSummary } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
 import { Elapsed } from '@polkadot/react-query';
-import { formatNumber } from '@polkadot/util';
+import { BN_ONE, formatNumber } from '@polkadot/util';
 
 import { useTranslation } from './translate';
 
@@ -36,7 +36,7 @@ function SummarySession ({ className, withEra = true, withSession = true }: Prop
       {sessionInfo && (
         <>
           {withSession && (
-            sessionInfo.sessionLength.gtn(1)
+            sessionInfo.sessionLength.gt(BN_ONE)
               ? (
                 <CardSummary
                   className={className}
@@ -56,7 +56,7 @@ function SummarySession ({ className, withEra = true, withSession = true }: Prop
               )
           )}
           {forcing && !forcing.isForceNone && withEra && (
-            sessionInfo.sessionLength.gtn(1)
+            sessionInfo.sessionLength.gt(BN_ONE)
               ? (
                 <CardSummary
                   className={className}
diff --git a/packages/page-parachains/src/Overview/Parachain.tsx b/packages/page-parachains/src/Overview/Parachain.tsx
index 2779a2b672..dbaff20079 100644
--- a/packages/page-parachains/src/Overview/Parachain.tsx
+++ b/packages/page-parachains/src/Overview/Parachain.tsx
@@ -11,7 +11,7 @@ import React, { useMemo } from 'react';
 import { Badge } from '@polkadot/react-components';
 import { useApi, useCall, useCallMulti, useParaApi } from '@polkadot/react-hooks';
 import { BlockToTime } from '@polkadot/react-query';
-import { formatNumber } from '@polkadot/util';
+import { BN_ONE, formatNumber } from '@polkadot/util';
 
 import { getChainLink, sliceHex } from '../util';
 
@@ -81,7 +81,7 @@ function Parachain ({ bestNumber, className = '', id, isScheduled, lastBacked, l
   const blockDelay = useMemo(
     () => bestNumber && (
       lastRelayNumber
-        ? bestNumber.sub(lastRelayNumber).subn(1)
+        ? bestNumber.sub(lastRelayNumber).isub(BN_ONE)
         : paraInfo.watermark
           ? bestNumber.sub(paraInfo.watermark)
           : undefined
diff --git a/packages/page-parachains/src/modals/Propose.tsx b/packages/page-parachains/src/modals/Propose.tsx
index c2868aadb6..749caa1bc2 100644
--- a/packages/page-parachains/src/modals/Propose.tsx
+++ b/packages/page-parachains/src/modals/Propose.tsx
@@ -8,7 +8,7 @@ import React, { useCallback, useState } from 'react';
 
 import { Button, Input, InputAddress, InputBalance, InputFile, InputNumber, InputWasm, MarkWarning, Modal, TxButton } from '@polkadot/react-components';
 import { useApi } from '@polkadot/react-hooks';
-import { BN_TEN, compactAddLength } from '@polkadot/util';
+import { BN_TEN, BN_THOUSAND, compactAddLength } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -50,7 +50,7 @@ function Propose ({ className, onClose }: Props): React.ReactElement<Props> {
   const [accountId, setAccountId] = useState<string | null>(null);
   const [name, setName] = useState('');
   const [paraId, setParaId] = useState(() => new BN(Date.now() % 131072));
-  const [balance, setBalance] = useState(() => new BN(1000).mul(BN_TEN.pow(new BN(api.registry.chainDecimals[0]))));
+  const [balance, setBalance] = useState(() => BN_THOUSAND.mul(BN_TEN.pow(new BN(api.registry.chainDecimals[0]))));
   const [validators, setValidators] = useState<string[]>(['']);
   const [{ isWasmValid, wasm }, setWasm] = useState<CodeState>({ isWasmValid: false, wasm: null });
   const [genesisState, setGenesisState] = useState<Uint8Array | null>(null);
diff --git a/packages/page-poll/src/index.tsx b/packages/page-poll/src/index.tsx
index 3932bb2c5d..d43bb2e26a 100644
--- a/packages/page-poll/src/index.tsx
+++ b/packages/page-poll/src/index.tsx
@@ -13,7 +13,7 @@ import styled from 'styled-components';
 import { Button, Columar, InputAddress, Progress, Spinner, Tabs, Toggle, TxButton } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
 import { BlockToTime, FormatBalance } from '@polkadot/react-query';
-import { BN_ONE, BN_ZERO, bnMax, formatBalance, formatNumber } from '@polkadot/util';
+import { BN_MILLION, BN_ONE, BN_ZERO, bnMax, formatBalance, formatNumber } from '@polkadot/util';
 
 import { useTranslation } from './translate';
 
@@ -27,8 +27,6 @@ interface Turnout {
   voted: BN;
 }
 
-const DIV = new BN(1_000_000);
-
 function PollApp ({ basePath, className }: Props): React.ReactElement<Props> {
   const { t } = useTranslation();
   const { api } = useApi();
@@ -53,7 +51,7 @@ function PollApp ({ basePath, className }: Props): React.ReactElement<Props> {
     if (totalIssuance && totals) {
       const max = bnMax(BN_ONE, ...totals);
 
-      setProgress(totals.map((total) => total.mul(DIV).div(max)));
+      setProgress(totals.map((total) => total.mul(BN_MILLION).div(max)));
 
       api.query.poll.voteOf
         .entries<ITuple<[Approvals, Balance]>>()
diff --git a/packages/page-staking/src/Actions/Account/InputValidationUnstakeThreshold.tsx b/packages/page-staking/src/Actions/Account/InputValidationUnstakeThreshold.tsx
index 34f4fa5a23..50aa1509f0 100644
--- a/packages/page-staking/src/Actions/Account/InputValidationUnstakeThreshold.tsx
+++ b/packages/page-staking/src/Actions/Account/InputValidationUnstakeThreshold.tsx
@@ -5,6 +5,7 @@ import BN from 'bn.js';
 import React, { useEffect, useState } from 'react';
 
 import { MarkWarning } from '@polkadot/react-components';
+import { BN_TEN } from '@polkadot/util';
 
 import { useTranslation } from '../../translate';
 
@@ -23,7 +24,7 @@ function InputValidationUnstakeThreshold ({ onError, unstakeThreshold }: Props):
 
       if (unstakeThreshold.ltn(0)) {
         newError = t<string>('The Threshold must be a positive number');
-      } else if (unstakeThreshold.gtn(10)) {
+      } else if (unstakeThreshold.gt(BN_TEN)) {
         newError = t<string>('The Threshold must lower than 11');
       }
 
diff --git a/packages/page-staking/src/Payouts/useStakerPayouts.ts b/packages/page-staking/src/Payouts/useStakerPayouts.ts
index 25ca435e0d..b8bed6187a 100644
--- a/packages/page-staking/src/Payouts/useStakerPayouts.ts
+++ b/packages/page-staking/src/Payouts/useStakerPayouts.ts
@@ -8,7 +8,7 @@ import BN from 'bn.js';
 import { useMemo } from 'react';
 
 import { useApi, useCall } from '@polkadot/react-hooks';
-import { isFunction } from '@polkadot/util';
+import { BN_BILLION, BN_ZERO, isFunction } from '@polkadot/util';
 
 export default function useStakerPayouts (): BN {
   const { api } = useApi();
@@ -17,8 +17,8 @@ export default function useStakerPayouts (): BN {
   return useMemo(
     () => (migrateEraOpt && migrateEraOpt.isSome && migrateEraOpt.unwrap()) || (
       isFunction(api.tx.staking.payoutStakers)
-        ? new BN(0)
-        : new BN(1_000_000_000)
+        ? BN_ZERO
+        : BN_BILLION
     ),
     [api, migrateEraOpt]
   );
diff --git a/packages/page-staking/src/Payouts/util.tsx b/packages/page-staking/src/Payouts/util.tsx
index df41060ad4..57555a8768 100644
--- a/packages/page-staking/src/Payouts/util.tsx
+++ b/packages/page-staking/src/Payouts/util.tsx
@@ -4,7 +4,7 @@
 import BN from 'bn.js';
 import React from 'react';
 
-import { formatNumber } from '@polkadot/util';
+import { BN_ONE, formatNumber } from '@polkadot/util';
 
 function isSingle (entry: BN | [BN, BN]): entry is BN {
   return !Array.isArray(entry);
@@ -24,13 +24,13 @@ export function createErasString (eras: BN[]): React.ReactNode {
         const last = result[result.length - 1];
 
         if (isSingle(last)) {
-          if (last.addn(1).eq(era)) {
+          if (last.add(BN_ONE).eq(era)) {
             result[result.length - 1] = [last, era];
           } else {
             result.push(era);
           }
         } else {
-          if (last[1].addn(1).eq(era)) {
+          if (last[1].add(BN_ONE).eq(era)) {
             last[1] = era;
           } else {
             result.push(era);
diff --git a/packages/page-staking/src/Query/ChartPrefs.tsx b/packages/page-staking/src/Query/ChartPrefs.tsx
index 41a2fd8c80..e9e8dbf63b 100644
--- a/packages/page-staking/src/Query/ChartPrefs.tsx
+++ b/packages/page-staking/src/Query/ChartPrefs.tsx
@@ -9,11 +9,11 @@ import React, { useMemo, useRef } from 'react';
 
 import { Chart, Spinner } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
+import { BN_BILLION } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
 const MULT = new BN(100 * 100);
-const BILLION = new BN(1_000_000_000);
 const COLORS_POINTS = [undefined, '#acacac'];
 
 function extractPrefs (prefs: DeriveStakerPrefs[] = []): ChartInfo {
@@ -24,7 +24,7 @@ function extractPrefs (prefs: DeriveStakerPrefs[] = []): ChartInfo {
   let total = 0;
 
   prefs.forEach(({ era, validatorPrefs }): void => {
-    const comm = validatorPrefs.commission.unwrap().mul(MULT).div(BILLION).toNumber() / 100;
+    const comm = validatorPrefs.commission.unwrap().mul(MULT).div(BN_BILLION).toNumber() / 100;
 
     total += comm;
     labels.push(era.toHuman());
diff --git a/packages/page-staking/src/Query/useBlockCounts.tsx b/packages/page-staking/src/Query/useBlockCounts.tsx
index 8bd5688cda..ce8de7e528 100644
--- a/packages/page-staking/src/Query/useBlockCounts.tsx
+++ b/packages/page-staking/src/Query/useBlockCounts.tsx
@@ -8,7 +8,7 @@ import type { SessionRewards } from '../types';
 import { useEffect, useState } from 'react';
 
 import { useApi, useCall, useIsMountedRef } from '@polkadot/react-hooks';
-import { isFunction } from '@polkadot/util';
+import { BN_ONE, BN_ZERO, isFunction } from '@polkadot/util';
 
 export default function useBlockCounts (accountId: string, sessionRewards: SessionRewards[]): u32[] {
   const { api } = useApi();
@@ -20,12 +20,12 @@ export default function useBlockCounts (accountId: string, sessionRewards: Sessi
 
   useEffect((): void => {
     if (isFunction(api.query.imOnline?.authoredBlocks) && sessionRewards && sessionRewards.length) {
-      const filtered = sessionRewards.filter(({ sessionIndex }): boolean => sessionIndex.gtn(0));
+      const filtered = sessionRewards.filter(({ sessionIndex }): boolean => sessionIndex.gt(BN_ZERO));
 
       if (filtered.length) {
         Promise
           .all(filtered.map(({ parentHash, sessionIndex }): Promise<u32> =>
-            api.query.imOnline.authoredBlocks.at(parentHash, sessionIndex.subn(1), accountId)
+            api.query.imOnline.authoredBlocks.at(parentHash, sessionIndex.sub(BN_ONE), accountId)
           ))
           .then((historic): void => {
             mountedRef.current && setHistoric(historic);
diff --git a/packages/page-staking/src/Query/util.ts b/packages/page-staking/src/Query/util.ts
index 9a2aeb00cd..8d81d40b33 100644
--- a/packages/page-staking/src/Query/util.ts
+++ b/packages/page-staking/src/Query/util.ts
@@ -3,7 +3,7 @@
 
 import BN from 'bn.js';
 
-import { BN_ZERO, isBn, isFunction } from '@polkadot/util';
+import { BN_THOUSAND, BN_ZERO, isBn, isFunction } from '@polkadot/util';
 
 interface ToBN {
   toBn: () => BN;
@@ -16,5 +16,5 @@ export function balanceToNumber (amount: BN | ToBN = BN_ZERO, divisor: BN): numb
       ? amount.toBn()
       : BN_ZERO;
 
-  return value.muln(1000).div(divisor).toNumber() / 1000;
+  return value.mul(BN_THOUSAND).div(divisor).toNumber() / 1000;
 }
diff --git a/packages/page-staking/src/Slashes/Summary.tsx b/packages/page-staking/src/Slashes/Summary.tsx
index fe5b9b53e3..fbb44c1e86 100644
--- a/packages/page-staking/src/Slashes/Summary.tsx
+++ b/packages/page-staking/src/Slashes/Summary.tsx
@@ -10,7 +10,7 @@ import React, { useMemo } from 'react';
 import { CardSummary, SummaryBox } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
 import { FormatBalance } from '@polkadot/react-query';
-import { formatNumber } from '@polkadot/util';
+import { BN_ONE, formatNumber } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -26,7 +26,7 @@ function Header ({ slash: { era, nominators, reporters, total, validators } }: P
   const [blockProgress, blockEnd] = useMemo(
     () => sessionInfo
       ? [
-        sessionInfo.activeEra.sub(era).subn(1).mul(sessionInfo.eraLength).add(sessionInfo.eraProgress),
+        sessionInfo.activeEra.sub(era).isub(BN_ONE).imul(sessionInfo.eraLength).iadd(sessionInfo.eraProgress),
         api.consts.staking.slashDeferDuration.mul(sessionInfo.eraLength)
       ]
       : [new BN(0), new BN(0)],
diff --git a/packages/page-staking/src/Targets/Summary.tsx b/packages/page-staking/src/Targets/Summary.tsx
index e283287f9c..b237c8d959 100644
--- a/packages/page-staking/src/Targets/Summary.tsx
+++ b/packages/page-staking/src/Targets/Summary.tsx
@@ -11,6 +11,7 @@ import React, { useMemo } from 'react';
 import { CardSummary, SummaryBox } from '@polkadot/react-components';
 import { useApi, useCall } from '@polkadot/react-hooks';
 import { FormatBalance } from '@polkadot/react-query';
+import { BN_ONE, BN_ZERO } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -29,7 +30,7 @@ const transformReward = {
 };
 
 const transformEra = {
-  transform: ({ activeEra }: DeriveSessionIndexes) => activeEra.gtn(0) ? activeEra.subn(1) : undefined
+  transform: ({ activeEra }: DeriveSessionIndexes) => activeEra.gt(BN_ZERO) ? activeEra.sub(BN_ONE) : undefined
 };
 
 function Summary ({ avgStaked, lowStaked, numNominators, numValidators, stakedReturn, totalIssuance, totalStaked }: Props): React.ReactElement<Props> {
diff --git a/packages/page-staking/src/Targets/index.tsx b/packages/page-staking/src/Targets/index.tsx
index 0832815a25..f8f0b2e439 100644
--- a/packages/page-staking/src/Targets/index.tsx
+++ b/packages/page-staking/src/Targets/index.tsx
@@ -11,6 +11,7 @@ import styled from 'styled-components';
 
 import { Button, Icon, Table, Toggle } from '@polkadot/react-components';
 import { useApi, useAvailableSlashes, useBlocksPerDays, useSavedFlags } from '@polkadot/react-hooks';
+import { BN_HUNDRED } from '@polkadot/util';
 
 import { MAX_NOMINATIONS } from '../constants';
 import ElectionBanner from '../ElectionBanner';
@@ -95,7 +96,7 @@ function applyFilter (validators: ValidatorInfo[], medianComm: number, allIdenti
           ? (commissionPer < MAX_COMM_PERCENT)
           : (!medianComm || (commissionPer <= medianComm)))
       ) &&
-      (!withoutOver || !maxPaid || maxPaid.muln(MAX_CAP_PERCENT).divn(100).gten(nomCount))
+      (!withoutOver || !maxPaid || maxPaid.muln(MAX_CAP_PERCENT).div(BN_HUNDRED).gten(nomCount))
     ) {
       if (!withGroup) {
         return true;
diff --git a/packages/page-staking/src/useSortedTargets.ts b/packages/page-staking/src/useSortedTargets.ts
index e73a644737..fa440f03bd 100644
--- a/packages/page-staking/src/useSortedTargets.ts
+++ b/packages/page-staking/src/useSortedTargets.ts
@@ -9,7 +9,7 @@ import BN from 'bn.js';
 import { useMemo } from 'react';
 
 import { calcInflation, useAccounts, useApi, useCall } from '@polkadot/react-hooks';
-import { arrayFlatten, BN_ONE, BN_ZERO } from '@polkadot/util';
+import { arrayFlatten, BN_MILLION, BN_ONE, BN_ZERO } from '@polkadot/util';
 
 interface LastEra {
   activeEra: BN;
@@ -82,7 +82,7 @@ function sortValidators (list: ValidatorInfo[]): ValidatorInfo[] {
 function extractSingle (api: ApiPromise, allAccounts: string[], derive: DeriveStakingElected | DeriveStakingWaiting, favorites: string[], { activeEra, eraLength, lastEra, sessionLength }: LastEra, historyDepth?: BN): [ValidatorInfo[], string[]] {
   const nominators: Record<string, boolean> = {};
   const emptyExposure = api.createType('Exposure');
-  const earliestEra = historyDepth && lastEra.sub(historyDepth).addn(1);
+  const earliestEra = historyDepth && lastEra.sub(historyDepth).iadd(BN_ONE);
   const list = derive.info.map(({ accountId, exposure = emptyExposure, stakingLedger, validatorPrefs }): ValidatorInfo => {
     // some overrides (e.g. Darwinia Crab) does not have the own/total field in Exposure
     let [bondOwn, bondTotal] = exposure.total
@@ -172,7 +172,7 @@ function extractInfo (api: ApiPromise, allAccounts: string[], electedDerive: Der
   // add the explicit stakedReturn
   !avgStaked.isZero() && elected.forEach((e): void => {
     if (!e.skipRewards) {
-      e.stakedReturn = inflation.stakedReturn * avgStaked.muln(1_000_000).div(e.bondTotal).toNumber() / 1_000_000;
+      e.stakedReturn = inflation.stakedReturn * avgStaked.mul(BN_MILLION).div(e.bondTotal).toNumber() / BN_MILLION.toNumber();
       e.stakedReturnCmp = e.stakedReturn * (100 - e.commissionPer) / 100;
     }
   });
diff --git a/packages/page-treasury/src/Overview/ProposalCreate.tsx b/packages/page-treasury/src/Overview/ProposalCreate.tsx
index 6f12b7d708..4a1b398d3a 100644
--- a/packages/page-treasury/src/Overview/ProposalCreate.tsx
+++ b/packages/page-treasury/src/Overview/ProposalCreate.tsx
@@ -6,6 +6,7 @@ import React, { useMemo, useState } from 'react';
 
 import { Button, InputAddress, InputBalance, MarkWarning, Modal, Static, TxButton } from '@polkadot/react-components';
 import { useApi, useToggle } from '@polkadot/react-hooks';
+import { BN_HUNDRED, BN_MILLION } from '@polkadot/util';
 
 import { useTranslation } from '../translate';
 
@@ -23,7 +24,7 @@ function Propose ({ className }: Props): React.ReactElement<Props> | null {
   const hasValue = value?.gtn(0);
 
   const bondPercentage = useMemo(
-    () => `${api.consts.treasury.proposalBond.muln(100).divn(1_000_000).toNumber().toFixed(2)}%`,
+    () => `${api.consts.treasury.proposalBond.mul(BN_HUNDRED).div(BN_MILLION).toNumber().toFixed(2)}%`,
     [api]
   );
 
diff --git a/packages/react-components/src/CardSummary.tsx b/packages/react-components/src/CardSummary.tsx
index 2b7bde00b9..a6e99bff60 100644
--- a/packages/react-components/src/CardSummary.tsx
+++ b/packages/react-components/src/CardSummary.tsx
@@ -9,7 +9,7 @@ import React from 'react';
 import styled from 'styled-components';
 
 import { BlockToTime } from '@polkadot/react-query';
-import { formatNumber, isUndefined } from '@polkadot/util';
+import { BN_HUNDRED, formatNumber, isUndefined } from '@polkadot/util';
 
 import Labelled from './Labelled';
 import Progress from './Progress';
@@ -43,7 +43,7 @@ function CardSummary ({ children, className = '', help, label, progress }: Props
         }`
         : (
           progress.isPercent
-            ? value.muln(100).div(total).toString()
+            ? value.mul(BN_HUNDRED).div(total).toString()
             : formatNumber(value)
         )
     )
diff --git a/packages/react-components/src/ConvictionDropdown.tsx b/packages/react-components/src/ConvictionDropdown.tsx
index fbabfba51a..3f317c3277 100644
--- a/packages/react-components/src/ConvictionDropdown.tsx
+++ b/packages/react-components/src/ConvictionDropdown.tsx
@@ -8,6 +8,7 @@ import React, { useRef } from 'react';
 
 import { ApiPromise } from '@polkadot/api';
 import { useApi, useBlockTime } from '@polkadot/react-hooks';
+import { BN_THOUSAND } from '@polkadot/util';
 
 import Dropdown from './Dropdown';
 import { useTranslation } from './translate';
@@ -30,7 +31,7 @@ function createOptions (api: ApiPromise, t: TFunction, blockTime: number): { tex
       text: t<string>('{{value}}x voting balance, locked for {{lock}}x enactment ({{period}} days)', {
         replace: {
           lock,
-          period: (bnLock.mul(api.consts.democracy.enactmentPeriod.muln(blockTime).divn(1000)).toNumber() / SEC_DAY).toFixed(2),
+          period: (bnLock.mul(api.consts.democracy.enactmentPeriod.muln(blockTime).div(BN_THOUSAND)).toNumber() / SEC_DAY).toFixed(2),
           value
         }
       }),
diff --git a/packages/react-components/src/InputNumber.tsx b/packages/react-components/src/InputNumber.tsx
index 8c07ddd0c1..8b8d4ddb9b 100644
--- a/packages/react-components/src/InputNumber.tsx
+++ b/packages/react-components/src/InputNumber.tsx
@@ -10,7 +10,7 @@ import React, { useCallback, useEffect, useState } from 'react';
 import styled from 'styled-components';
 
 import { useApi } from '@polkadot/react-hooks';
-import { BN_TEN, BN_ZERO, formatBalance, isBn } from '@polkadot/util';
+import { BN_ONE, BN_TEN, BN_TWO, BN_ZERO, formatBalance, isBn } from '@polkadot/util';
 
 import { BitLengthOption } from './constants';
 import Dropdown from './Dropdown';
@@ -56,7 +56,7 @@ export class TokenUnit {
 }
 
 function getGlobalMaxValue (bitLength?: number): BN {
-  return new BN(2).pow(new BN(bitLength || DEFAULT_BITLENGTH)).subn(1);
+  return BN_TWO.pow(new BN(bitLength || DEFAULT_BITLENGTH)).isub(BN_ONE);
 }
 
 function getRegex (isDecimal: boolean): RegExp {
diff --git a/packages/react-hooks/src/useAvailableSlashes.ts b/packages/react-hooks/src/useAvailableSlashes.ts
index d4000cd065..e95b7cee09 100644
--- a/packages/react-hooks/src/useAvailableSlashes.ts
+++ b/packages/react-hooks/src/useAvailableSlashes.ts
@@ -9,6 +9,7 @@ import BN from 'bn.js';
 import { useEffect, useState } from 'react';
 
 import { useApi, useCall, useIsMountedRef } from '@polkadot/react-hooks';
+import { BN_ONE } from '@polkadot/util';
 
 type Unsub = () => void;
 
@@ -30,7 +31,7 @@ export function useAvailableSlashes (): [BN, UnappliedSlash[]][] {
       // any <= activeEra (we include activeEra since slashes are immediately reflected)
       while (start.lte(indexes.activeEra)) {
         range.push(start);
-        start = start.addn(1);
+        start = start.iadd(BN_ONE);
       }
 
       if (range.length) {
diff --git a/packages/react-hooks/src/useInflation.ts b/packages/react-hooks/src/useInflation.ts
index 0a1092c260..adeeb90220 100644
--- a/packages/react-hooks/src/useInflation.ts
+++ b/packages/react-hooks/src/useInflation.ts
@@ -8,13 +8,14 @@ import BN from 'bn.js';
 import { useEffect, useState } from 'react';
 
 import { getInflationParams } from '@polkadot/apps-config';
+import { BN_MILLION } from '@polkadot/util';
 
 import { useApi } from './useApi';
 import { useCall } from './useCall';
 
 export function calcInflation (api: ApiPromise, totalStaked: BN, totalIssuance: BN): Inflation {
   const { falloff, idealStake, maxInflation, minInflation } = getInflationParams(api);
-  const stakedFraction = totalStaked.muln(1_000_000).div(totalIssuance).toNumber() / 1_000_000;
+  const stakedFraction = totalStaked.mul(BN_MILLION).div(totalIssuance).toNumber() / BN_MILLION.toNumber();
   const idealInterest = maxInflation / idealStake;
   const inflation = 100 * (minInflation + (
     stakedFraction <= idealStake
diff --git a/packages/react-hooks/src/useTreasury.ts b/packages/react-hooks/src/useTreasury.ts
index 644853b203..7e33ffa9ca 100644
--- a/packages/react-hooks/src/useTreasury.ts
+++ b/packages/react-hooks/src/useTreasury.ts
@@ -9,9 +9,8 @@ import { useEffect, useState } from 'react';
 import { DeriveBalancesAccount } from '@polkadot/api-derive/types';
 import { useApi } from '@polkadot/react-hooks/useApi';
 import { useCall } from '@polkadot/react-hooks/useCall';
-import { BN_ZERO, stringToU8a } from '@polkadot/util';
+import { BN_MILLION, BN_ZERO, stringToU8a } from '@polkadot/util';
 
-const PM_DIV = new BN(1000000);
 const TREASURY_ACCOUNT = stringToU8a('modlpy/trsry'.padEnd(32, '\0'));
 
 interface Treasury {
@@ -38,7 +37,7 @@ export function useTreasury (): Treasury {
       ? treasuryBalance.freeBalance
       : undefined);
     setBurn(treasuryBalance?.freeBalance.gtn(0) && !api.consts.treasury.burn.isZero()
-      ? api.consts.treasury.burn.mul(treasuryBalance?.freeBalance).div(PM_DIV)
+      ? api.consts.treasury.burn.mul(treasuryBalance.freeBalance).div(BN_MILLION)
       : BN_ZERO);
   }, [api, treasuryBalance, spendPeriod]);