# Addition and Subtraction within 100

*Time: 15 min. 6 questions.*

## Instructions

Answer all six questions. You may draw pictures or use objects to help you. Show your thinking when a question asks you to. Write your answers clearly on the lines provided.

## Questions

1. Which number sentence shows a way to decompose 25 + 30?
 A) 20 + 5 + 30
 B) 25 + 3 + 0
 C) 25 + 10 + 10 + 10
 D) 25 + 20 + 20
 ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

2. Sam has 15 stickers. He gets 12 more stickers. How many stickers does Sam have now? Show your thinking.
 ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

3. True or false: 40 + 20 = 50 + 10
 ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844))

4. Find the missing number: 35 + ___ = 50
 ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

5. Maya counts 28 beads in one pile and 22 beads in another pile. How many beads does she have altogether?
 ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

6. Write a number sentence that adds three numbers to make 40. (Example: 10 + 10 + 20 = 40)
 ([Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846))

## Curriculum Coverage

| Question | Learning Outcome |
|---|---|
| 1 | [Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) |
| 2 | [Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) |
| 3 | [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844) |
| 4 | [Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) |
| 5 | [Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) |
| 6 | [Details](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) |

## Answer Key

1. **A) 20 + 5 + 30 or C) 25 + 10 + 10 + 10**
 Both decompositions are valid ways to show 25 + 30. Option A breaks 25 into tens and ones (20 + 5), while option C breaks 30 into three tens. Either answer demonstrates understanding of how numbers can be composed in multiple ways.

2. **27 stickers**
 15 + 12 = 27 (students may count on, use tens and ones, or draw a picture).

3. **True**
 Both sides equal 60, showing that sums can be composed in different ways.

4. **15**
 35 + 15 = 50 (students use inverse operations or count up from 35 to 50).

5. **50 beads**
 28 + 22 = 50 (students may use the strategy of making a multiple of ten: 28 + 2 = 30, then 30 + 20 = 50).

6. **Answers vary. Examples: 10 + 15 + 15 = 40; 20 + 10 + 10 = 40; 5 + 15 + 20 = 40**
 Any three addends that sum to 40 show understanding that a sum can be composed in multiple ways.

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*AILI quiz · language en · model claude-haiku-4-5-20251001 · generated 2026-09-17 · id 1fc10ee7-6523-4e94-a7bc-6b2b2af8e15b*

### 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)