# Addition and Subtraction Within 100

Today you will add and subtract two-digit numbers. You will also check your work and find missing numbers, just like Grade 2 mathematicians do ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)).

## Exercises

**1. Add these numbers.** Look for doubles or a way to make a ten to help you ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

a) 24 + 13 = ______

b) 36 + 36 = ______

c) 8 + 9 + 2 = ______

d) 47 + 20 = ______

**2. Subtract these numbers.** ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

a) 58 − 25 = ______

b) 90 − 40 = ______

c) 63 − 17 = ______

d) 100 − 55 = ______

**3. Find the missing number.** ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

a) 30 + ______ = 70

b) ______ − 12 = 40

c) 45 + ______ = 100

d) 82 − ______ = 60

**4. Check each sum using subtraction.** Write the subtraction fact that checks it ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

| Addition fact | Check with subtraction |
|---|---|
| 26 + 14 = 40 | ______ |
| 55 + 35 = 90 | ______ |
| 18 + 22 = 40 | ______ |

**5. Circle the correct answer.** ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

47 + 26 =?

A) 63 B) 73 C) 83 D) 93

100 − 38 =?

A) 52 B) 62 C) 72 D) 68

**6. Solve the word problem.** Show your work in the box ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

Mia has 45 stickers. Her friend gives her 28 more stickers.

How many stickers does Mia have now?

Work space:

______________________________________

______________________________________

Answer: ______ stickers

## Answer key

1. a) 37 b) 72 c) 19 d) 67
2. a) 33 b) 50 c) 46 d) 45
3. a) 40 b) 52 c) 55 d) 22
4. 40 − 14 = 26 (or 40 − 26 = 14); 90 − 35 = 55 (or 90 − 55 = 35); 40 − 22 = 18 (or 40 − 18 = 22)
5. First: B) 73. Second: B) 62
6. 73 stickers

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*AILI homework sheet · language en · model claude-sonnet-5 · generated 2026-09-17 · id f5412f53-8506-46c0-8d34-b914cab13fd6*

### Sources

- node:n1: Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29820)
- node:n2: How can addition and subtraction be interpreted? (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29843)
- node:n3: Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)
- node:n4: Details (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)