Find two numbers based on sum and difference
Key points :
Sum and Difference Defined:
- Sum: When you add two numbers together, you get their sum. For example, if you have apples: 2 apples + 3 apples = 5 apples.
- Difference: When you subtract one number from another, you get their difference. For example, if you have 5 apples and you eat 2 apples, the difference is 3 apples left.
Finding Two Numbers:
- If you know the sum (total when added together) and the difference (how much one number is smaller than the other), you can find the two numbers.
Learn with an example
🗼 The sum of two numbers is 13, and their difference is 1.
What are the two numbers?____ and_____
- Think of pairs of numbers whose difference is 1. Then find the sum of each pair.
| Difference | Sum |
| 2 − 1 = 1 | 2 + 1 = 3 |
| 3 − 2 = 1 | 3 + 2 = 5 |
| 4 − 3 = 1 | 4 + 3 = 7 |
| 5 − 4 = 1 | 5 + 4 = 9 |
| 6 − 5 = 1 | 6 + 5 = 11 |
| 7 − 6 = 1 | 7 + 6 = 13 |
- The numbers are 7 and 6.
🗼 The sum of two numbers is 13. Their difference is 11.
What are the two numbers?____ and ____
- Think of pairs of numbers whose difference is 11. Then find the sum of each pair.
| Difference | Sum |
| 12 − 1 = 11 | 12 + 1 = 13 |
| 13 − 2 = 11 | 13 + 2 = 15 |
| 14 − 3 = 11 | 14 + 3 = 17 |
- The numbers are 12 and 1.
🗼 The difference of two numbers is 1, and their sum is 13.
What are the two numbers?____ and ____
- Think of pairs of numbers whose difference is 1. Then find the sum of each pair.
| Difference | Sum |
| 2 − 1 = 1 | 2 + 1 = 3 |
| 3 − 2 = 1 | 3 + 2 = 5 |
| 4 − 3 = 1 | 4 + 3 = 7 |
| 5 − 4 = 1 | 5 + 4 = 9 |
| 6 − 5 = 1 | 6 + 5 = 11 |
| 7 − 6 = 1 | 7 + 6 = 13 |
- The numbers are 7 and 6.
Let’s practice!🖊️
