Sarah borrowed 12 books from the library. She returned 4 books and then borrowed 3 more. How many books does she have now?
12 - 4 + 3 = 11
Jake invited 5 friends to his birthday party. Each friend brings 2 balloons, and Jake had 10 balloons himself. How many balloons are there in total?
5 • 2 + 10 = 20
Maria planted 15 flowers in her garden. Later, she planted 7 more flowers and gave away 4 to her neighbor. How many flowers does she have left?
15 + 7 - 4 = 18 flowers