3 files changed, 9 insertions, 1 deletions
diff --git a/packages/contract-wrappers/src/utils/constants.ts b/packages/contract-wrappers/src/utils/constants.ts
index 2df11538c..78441decf 100644
--- a/packages/contract-wrappers/src/utils/constants.ts
+++ b/packages/contract-wrappers/src/utils/constants.ts
@@ -12,4 +12,6 @@ export const constants = {
     UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
     DEFAULT_BLOCK_POLLING_INTERVAL: 1000,
     ZERO_AMOUNT: new BigNumber(0),
+    ONE_AMOUNT: new BigNumber(1),
+    ETHER_TOKEN_DECIMALS: 18,
 };
diff --git a/packages/contract-wrappers/src/utils/decorators.ts b/packages/contract-wrappers/src/utils/decorators.ts
index 6e77450e8..d6bf6ec1e 100644
--- a/packages/contract-wrappers/src/utils/decorators.ts
+++ b/packages/contract-wrappers/src/utils/decorators.ts
@@ -24,7 +24,7 @@ const contractCallErrorTransformer = (error: Error) => {
 const schemaErrorTransformer = (error: Error) => {
     if (_.includes(error.message, constants.INVALID_TAKER_FORMAT)) {
         const errMsg =
-            'Order taker must be of type string. If you want anyone to be able to fill an order - pass ZeroEx.NULL_ADDRESS';
+            'Order taker must be of type string. If you want anyone to be able to fill an order - pass NULL_ADDRESS';
         return new Error(errMsg);
     }
     return error;
diff --git a/packages/contract-wrappers/src/utils/utils.ts b/packages/contract-wrappers/src/utils/utils.ts
index 689a7ee0a..f7949ec34 100644
--- a/packages/contract-wrappers/src/utils/utils.ts
+++ b/packages/contract-wrappers/src/utils/utils.ts
@@ -1,4 +1,7 @@
 import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+
+import { constants } from './constants';
 
 export const utils = {
     getCurrentUnixTimestampSec(): BigNumber {
@@ -8,4 +11,7 @@ export const utils = {
     getCurrentUnixTimestampMs(): BigNumber {
         return new BigNumber(Date.now());
     },
+    numberPercentageToEtherTokenAmountPercentage(percentage: number): BigNumber {
+        return Web3Wrapper.toBaseUnitAmount(constants.ONE_AMOUNT, constants.ETHER_TOKEN_DECIMALS).mul(percentage);
+    },
 };