# Decompose Once to Subtract

Examples, solutions, and videos to help Grade 3 students learn how to decompose once to subtract measurements including three-digit minuends with zeros in the tens and ones places.

Common Core Standards: 3.NBT.2, 3.NBT.1, 3.MD.1, 3.MD.2

### New York State Common Core Math Grade 3, Module 2, Lesson 18

Homework

1. Solve the subtraction problems below.
b. 370 L - 46 L
j. 837 km - 645 km
2. A magazine weighs 280 grams less than a newspaper. The weight of the newspaper is shown below. How much does the magazine weigh? Use a tape diagram to model your thinking.
3. The chart to the right shows how long 3 games take.
a. Francesca’s basketball game is 22 minutes shorter than Lucas’ baseball game. How long is Francesca’s basketball game? b. How much longer is Francesca’s basketball game than Joey’s football game?

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations. 