Learn

Sometimes, we need to adjust the value of a variable.

Imagine we’re working at a bake sale and want to keep track of how many cupcakes we have by creating a variable called `numCupcakes`:

``int numCupcakes = 12;``

If we baked `8` more cupcakes, we know that we could update our variable using the `+` operator:

``numCupcakes = numCupcakes + 8; // Value is now 20``

While this method works just fine, we had to write our variable `numCupcakes` twice. We can shorten this syntax by using a compound assignment operator.

Compound assignment operators perform an arithmetic operation on a variable and then reassigns its value. Using the `+=` compound assignment operator, we can rewrite our previous code like so:

``numCupcakes += 8; // Value is now 20``

Now we only need to reference `numCupcakes` once.

We can use compound assignment operators for all of the arithmetic operators we’ve covered:

• Addition (`+=`)
• Subtraction (`-=`)
• Multiplication (`*=`)
• Division (`/=`)
• Modulo (`%=`)

### Instructions

1.

You are also in charge of keeping track of how many cookies there are at the bake sale. This value is represented by the variable `numCookies`.

A customer comes and buys `3` cookies. Use the appropriate compound assignment operator to reflect this change.

2.