Ways to make a number – subtraction sentences
key notes :
Introduction to Subtraction Sentences
- A subtraction sentence includes a minuend (starting number), subtrahend (number taken away), and difference (result).
- Example: 8 – 5 = 3.
Understanding the Concept
- Explain that subtraction shows how many are left when some are taken away.
- Use objects (e.g., blocks, counters) to visualize subtraction.
Breaking Down a Number Using Subtraction
Highlight that a number can be broken into smaller parts using subtraction.
Example for 7:
- 7 – 0 = 7
- 7 – 1 = 6
- 7 – 2 = 5
Multiple Subtraction Sentences for the Same Number
Encourage students to find all possible subtraction sentences for a given number.
Example for 5:
- 5 – 0 = 5
- 5 – 1 = 4
- 5 – 2 = 3
Zero in Subtraction
- Explain the role of zero in subtraction: Subtracting zero leaves the number unchanged.
- Example: 6 – 0 = 6.
Learn with an example
ðŸ”Here are some ways to make 1. Find the pattern and type the missing subtraction number sentence.
| 5 − 4 = 1 |
| 4 − 3 = 1 |
| 3 − 2 = 1 |
| 1 − 0 = 1 |
- Find the first number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing subtraction number sentence must start with 2.
- Now find the second number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing number must be 1. The second number in the missing subtraction number sentence is 1.
- The missing subtraction number sentence starts with 2 − 1. This is a way to make 1. The missing subtraction number sentence is 2 − 1 = 1.
ðŸ”Here are some ways to make 0. Find the pattern and type the missing subtraction number sentence.
| 4 − 4 = 0 |
| 3 − 3 = 0 |
| 2 − 2 = 0 |
| 0 − 0 = 0 |
- Find the first number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing subtraction number sentence must start with 1.
- Now find the second number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing number must be 1. The second number in the missing subtraction number sentence is 1.
- The missing subtraction number sentence starts with 1 − 1. This is a way to make 0. The missing subtraction number sentence is 1 − 1 = 0.
ðŸ”Here are some ways to make 0. Find the pattern and type the missing subtraction number sentence.
| 5 − 5 = 0 |
| 4 − 4 = 0 |
| 2 − 2 = 0 |
| 1 − 1 = 0 |
- Find the first number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing subtraction number sentence must start with 3.
- Now find the second number in each subtraction number sentence. Look for a pattern. Each number is one less than the number above it. To complete the pattern, the missing number must be 3. The second number in the missing subtraction number sentence is 3.
- The missing subtraction number sentence starts with 3 − 3. This is a way to make 0. The missing subtraction number sentence is 3 − 3 = 0.
Let’s practice!
