You have 12 balloons to blow up for a party. you blow up 1/3 of them and your friend blows up five of them. what fraction of the balloons need to be blown up

Given:
12 balloons
1/3 I blew up
5 my friend blew up.

1/3 * 12 = 12/3 = 4
4 + 5 = 9 number of balloons blown up.

12 - 9 = 3 number of balloons that need to be blown up.

3/12 = 1/4 is the fraction of the balloons needed to be blown up.

Multiplication property of zero