# Addition and Subtraction Within 100

This sheet helps you practice math. You will add and subtract numbers up to 100 ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)). You will use number facts. Doubles are two of the same number added together. Inverse operations are opposite math moves. You use them to check your work. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

## Exercises

**1. Quick Facts**
Fill in the missing number. These are addition and subtraction facts to 10. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

6 + 4 = ______
9 − 3 = ______
7 + ______ = 10
______ − 5 = 5

**2. Two-Digit Addition and Subtraction**
Solve each problem. You can make a ten to help. You can use doubles too. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

34 + 25 = ______
58 − 23 = ______
47 + 16 = ______
82 − 39 = ______

**3. Composing 100**
Show two ways to make 100. Use tens to do it. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

Way 1: ______ + ______ = 100
Way 2: ______ + ______ + ______ = 100

**4. Missing Number**
Find the missing number. Look at each sum or difference. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

30 + ______ = 60
______ + 15 = 40
90 − ______ = 50
______ − 20 = 45

**5. Check with the Inverse**
Solve the problem. Then write the opposite operation to check your answer. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

Problem: 48 + 27 = ______
Check: ______ − ______ = ______

Problem: 73 − 26 = ______
Check: ______ + ______ = ______

**6. Word Problem**
Read the story. Write a number sentence and solve. ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)).

Maria has 38 stickers. Her friend gives her 45 more stickers. How many stickers does Maria have now?

Number sentence: ______________________
Answer: ______ stickers

A garden has 72 flowers. 27 flowers are picked. How many flowers are left?

Number sentence: ______________________
Answer: ______ flowers

## Answer Key

1. 6 + 4 = 10; 9 − 3 = 6; 7 + 3 = 10; 10 − 5 = 5
2. 34 + 25 = 59; 58 − 23 = 35; 47 + 16 = 63; 82 − 39 = 43
3. Way 1: 40 + 60 = 100 (answers vary); Way 2: 30 + 30 + 40 = 100 (answers vary)
4. 30 + 30 = 60; 25 + 15 = 40; 90 − 40 = 50; 65 − 20 = 45
5. 48 + 27 = 75, check: 75 − 27 = 48; 73 − 26 = 47, check: 47 + 26 = 73
6. 38 + 45 = 83 stickers; 72 − 27 = 45 flowers

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*AILI homework sheet · language en · model claude-sonnet-5 · generated 2026-09-17 · id 5eb8fb45-dc2d-4f25-b32f-5a1d77dff354*

### 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)