Part 2: Addition and Subtraction

# 2.3: Word problems for adding and subtracting with positive integers

Notes

##### Adding a positive integer to a positive integer

**Add To Problem**: The most straightforward type of word problem for adding a positive integer to a positive integer is to simply add B objects to A similar objects to get A + B objects in total. For example,

- Arithmetic problem: Solve 7 + 4.
- Word problem: Susi has 7 toy cars, while Felix has 4 toy cars. How many toy cars do Susi and Felix have together?
- 7 + 4 = 11, so Susi and Felix have 11 toy cars together.

##### Subtracting a positive integer from a larger positive integer

**Take From Problem**: One type of word problem for subtracting a positive integer from a larger positive integer is to take B objects from A objects to leave A – B objects. For example,

- Arithmetic problem: Solve 7 – 4.
- Word problem: Susi has 7 toy cars and Felix took 4 of Susi’s cars away. How many toy cars does Susi have left?
- 7 – 4 = 3, so Susi has 3 toy cars left.

**Compare Problem**: Another type of word problem for subtracting a positive integer from a larger positive integer is to consider the difference between B objects and A similar objects. For example,

- Arithmetic problem: Solve 7 – 4.
- Word problem: Susi has 7 toy cars, while Felix has 4 toy cars. How many more toy cars does Susi have than Felix?
- 7 – 4 = 3, so Susi has 3 more toy cars than Felix.

The video below works through some examples of word problems for adding and subtracting with positive integers.

Video Tips

Practice Exercises

Do the following exercises to practice matching positive integer addition/subtraction problems and word problems.