Each batch of cookie mix needs 0.4 cups of sugar, and each batch can make 16 cookies. If Ashley is making 4 batches of cookies, how much sugar does she need

1.6 cups

Explanation:

Let's make a proportion using the following set up.

cups of sugar/batches=cups of sugar/batches

We know that 0.4 cups of sugar are needed for 1 batch of cookies. We don't know how many cups of sugar are needed for 4 batches. Therefore, we can say that x cups of sugar are needed for 4 batches.

0.4 cups of sugar/1 batch=x cups of sugar/4 batches

0.4/1=x/4

We want to find out what x (cups of sugar for 4 batches) is. In order to do this, we have to get x by itself. Perform the opposite of what is being done to the equation. Keep in mind, everything done to one side, has to be done to the other.

x is being divided by 4. The opposite of division is multiplication. Multiply both sides of the equation by 4.

4 * (0.4/1) = (x/4) * 4

4 * (0.4/1) = x

4*0.4=x

1.6=x

Add appropriate units. IN this case, the units are cups.

x=1.6 cups

4 batches of cookies will require 1.6 cups of sugar.