Using the following code:

```
// readline-sync stuff here
function add(a, b){
return a + b;
}
function subtract(a, b){
return a - b;
}
function multiply(a, b){
return a * b;
}
function divide(a, b){
return a / b;
}
function calculate(a, b, operationFunction){
//your code here.
}
```

Make a calculator that will take 3 inputs from a user.

2 numbers and an operator. The calculate function will log to the console the answer.