# Addition and Subtraction Within 100

*30 minutes, 3 stages*

You are learning to add and subtract numbers up to 100 in ways that make sense to you ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)). Today you will practise using strategies like making groups of ten and checking your work with the opposite operation ([Knowledge](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29850), [Skills](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852)).

## Stage 1: Quick Facts (8 min)

Write the answer to each addition and subtraction fact. These are number facts you know by heart.

1. 5 + 3 = ___
2. 7 + 2 = ___
3. 8 + 4 = ___
4. 9 − 4 = ___
5. 10 − 6 = ___
6. 6 + 6 = ___
7. 3 + 5 = ___
8. 12 − 5 = ___

Now write one more fact of your own. Pick any two numbers that add to 10 or less, and write them as an addition problem.

## Stage 2: Two-Digit Problems (14 min)

Solve each problem. You can draw tens and ones, use a number line, or count on your fingers. Show your thinking.

**Problem A:** 24 + 13 = ___

How did you solve it? Write or draw your way.

**Problem B:** 35 + 20 = ___

**Problem C:** 48 − 10 = ___

**Problem D:** 52 + 15 = ___

**Problem E:** 67 − 5 = ___

Check one of your answers using the opposite operation. For example, if you solved 24 + 13, try 37 − 13 to see if you get 24 again. Write which problem you checked and what you found.

## Stage 3: Real-World Addition (8 min)

Read each problem and write the number sentence (the math) and the answer.

**Problem 1:** You have 28 stickers. Your friend gives you 12 more. How many stickers do you have now?

Number sentence: ___ + ___ = ___

Answer: ___ stickers

**Problem 2:** There are 45 crayons in the box. You use 13 of them. How many are left?

Number sentence: ___ − ___ = ___

Answer: ___ crayons

## Self-check

Answer these questions to see what you understand:

1. Can you add two two-digit numbers and explain one way you did it (such as making tens or counting on)?

2. When you subtract, how can you check that your answer is right? (Hint: think about the opposite operation.)

3. Did you finish all three stages? Which one felt easiest, and which one was tricky?

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*AILI student homework · language en · model claude-haiku-4-5-20251001 · generated 2026-09-17 · id d8cbeed8-7b4c-40f7-af30-37b624377990*

### Sources

- node:n1: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29843)
- node:n2: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)
- node:n3: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)
- node:n4: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29848)
- node:n5: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29847)
- node:n6: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29850)
- node:n7: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852)
- node:n8: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29851)
- node:n9: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852)
- node:n10: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29850)
- node:n11: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29848)
- node:n12: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844)
- node:n13: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29847)
- node:n14: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29851)
- node:n15: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846)