**The aim of this puzzle**: Use the subtraction assignment `-=`

operator to subtract from a variable.

**Walkthrough of the solution**: When updating the value of a variable, a new value must be assigned to the variable. The usual way to do this would be something like:

```
let x = 5;
x = x - 2;
```

This tells the code, “Take the current value of `x`

(which is 5), subtract 2, and reassign it to `x`

.” `x`

would now equal 3.

A shorter way to write this is to use the `-=`

operator:

```
let x = 5;
x -= 2;
```

Is the same as:

```
let x = 5;
x = x - 2;
```

To complete this puzzle, use the `-=`

operator to subtract `purchase`

from `wallet`

.

**Sample code solution**:

(Tap below to reveal)

```
let wallet = 80;
let purchase = 35;
wallet -= purchase;
console.log('Wallet is now ' + wallet);
```

**JavaScript Concepts**: Subtraction Assignment Operator, Variable Declarations with Let