Syncloop offers a transformation with custom JavaScript code. So users can add custom JavaScript native functions while mapping two fields & also users can evaluate javascript expression in a variable.
1. When you do the mapping now select the variable(select the mapping) as shown in the image.
2. Now click on the Custom Mapping Configuration icon 
3. Now in the popup in the “Apply logic on value” section select method as custom.
4. Now add the JavaScript as shown in the image.
5. Math.pow is a Native JavaScript function & it will execute while transforming the value in fields.
Create a new variable, assign an expression in javascript and select the evaluation as Evaluate expressions as shown in the image.
That's all. Now you new variable will have a value from javascript expression.
