Answer :
Sure, let's go through the additions step-by-step using mental math:
1. 89 + 46:
- Break it down: [tex]\( 89 + 1 = 90 \)[/tex]
- Then add the rest: [tex]\( 90 + 45 = 135 \)[/tex]
- So, [tex]\( 89 + 46 = 135 \)[/tex]
2. 301 + 61:
- [tex]\( 301 + 60 = 361 \)[/tex]
- Then add the remaining 1: [tex]\( 361 + 1 = 362 \)[/tex]
- Therefore, [tex]\( 301 + 61 = 362 \)[/tex]
3. 400 + 157:
- [tex]\( 400 + 100 = 500 \)[/tex]
- [tex]\( 500 + 50 = 550 \)[/tex]
- Finally, [tex]\( 550 + 7 = 557 \)[/tex]
- So, [tex]\( 400 + 157 = 557 \)[/tex]
4. 722 + 158:
- [tex]\( 722 + 150 = 872 \)[/tex]
- [tex]\( 872 + 8 = 880 \)[/tex]
- Therefore, [tex]\( 722 + 158 = 880 \)[/tex]
5. 523 + 223:
- [tex]\( 523 + 200 = 723 \)[/tex]
- [tex]\( 723 + 20 = 743 \)[/tex]
- [tex]\( 743 + 3 = 746 \)[/tex]
- So, [tex]\( 523 + 223 = 746 \)[/tex]
6. 804 + 396:
- [tex]\( 804 + 400 = 1204 \)[/tex]
- Subtracting the extra: [tex]\( 1204 - 4 = 1200 \)[/tex]
- So, [tex]\( 804 + 396 = 1200 \)[/tex]
7. 299 + 206:
- [tex]\( 299 + 200 = 499 \)[/tex]
- [tex]\( 499 + 6 = 505 \)[/tex]
- Therefore, [tex]\( 299 + 206 = 505 \)[/tex]
8. 878 + 534:
- [tex]\( 878 + 500 = 1378 \)[/tex]
- [tex]\( 1378 + 30 = 1408 \)[/tex]
- [tex]\( 1408 + 4 = 1412 \)[/tex]
- So, [tex]\( 878 + 534 = 1412 \)[/tex]
9. 1,000 + 7,000:
- Adding directly: [tex]\( 1000 + 7000 = 8000 \)[/tex]
- Therefore, [tex]\( 1,000 + 7,000 = 8000 \)[/tex]
10. Reasoning: How can you write [tex]\( 52 + (8 + 25) \)[/tex] to make it easier to add?
- By regrouping: [tex]\( (52 + 25) + 8 \)[/tex]
- [tex]\( 52 + 25 = 77 \)[/tex]
- [tex]\( 77 + 8 = 85 \)[/tex]
- This makes the addition easier, so [tex]\( 52 + (8 + 25) = 85 \)[/tex]
The final answers are:
1. [tex]\( 135 \)[/tex]
2. [tex]\( 362 \)[/tex]
3. [tex]\( 557 \)[/tex]
4. [tex]\( 880 \)[/tex]
5. [tex]\( 746 \)[/tex]
6. [tex]\( 1200 \)[/tex]
7. [tex]\( 505 \)[/tex]
8. [tex]\( 1412 \)[/tex]
9. [tex]\( 8000 \)[/tex]
10. The value is [tex]\( 85 \)[/tex] when reorganized as [tex]\( (52 + 25) + 8 \)[/tex].
1. 89 + 46:
- Break it down: [tex]\( 89 + 1 = 90 \)[/tex]
- Then add the rest: [tex]\( 90 + 45 = 135 \)[/tex]
- So, [tex]\( 89 + 46 = 135 \)[/tex]
2. 301 + 61:
- [tex]\( 301 + 60 = 361 \)[/tex]
- Then add the remaining 1: [tex]\( 361 + 1 = 362 \)[/tex]
- Therefore, [tex]\( 301 + 61 = 362 \)[/tex]
3. 400 + 157:
- [tex]\( 400 + 100 = 500 \)[/tex]
- [tex]\( 500 + 50 = 550 \)[/tex]
- Finally, [tex]\( 550 + 7 = 557 \)[/tex]
- So, [tex]\( 400 + 157 = 557 \)[/tex]
4. 722 + 158:
- [tex]\( 722 + 150 = 872 \)[/tex]
- [tex]\( 872 + 8 = 880 \)[/tex]
- Therefore, [tex]\( 722 + 158 = 880 \)[/tex]
5. 523 + 223:
- [tex]\( 523 + 200 = 723 \)[/tex]
- [tex]\( 723 + 20 = 743 \)[/tex]
- [tex]\( 743 + 3 = 746 \)[/tex]
- So, [tex]\( 523 + 223 = 746 \)[/tex]
6. 804 + 396:
- [tex]\( 804 + 400 = 1204 \)[/tex]
- Subtracting the extra: [tex]\( 1204 - 4 = 1200 \)[/tex]
- So, [tex]\( 804 + 396 = 1200 \)[/tex]
7. 299 + 206:
- [tex]\( 299 + 200 = 499 \)[/tex]
- [tex]\( 499 + 6 = 505 \)[/tex]
- Therefore, [tex]\( 299 + 206 = 505 \)[/tex]
8. 878 + 534:
- [tex]\( 878 + 500 = 1378 \)[/tex]
- [tex]\( 1378 + 30 = 1408 \)[/tex]
- [tex]\( 1408 + 4 = 1412 \)[/tex]
- So, [tex]\( 878 + 534 = 1412 \)[/tex]
9. 1,000 + 7,000:
- Adding directly: [tex]\( 1000 + 7000 = 8000 \)[/tex]
- Therefore, [tex]\( 1,000 + 7,000 = 8000 \)[/tex]
10. Reasoning: How can you write [tex]\( 52 + (8 + 25) \)[/tex] to make it easier to add?
- By regrouping: [tex]\( (52 + 25) + 8 \)[/tex]
- [tex]\( 52 + 25 = 77 \)[/tex]
- [tex]\( 77 + 8 = 85 \)[/tex]
- This makes the addition easier, so [tex]\( 52 + (8 + 25) = 85 \)[/tex]
The final answers are:
1. [tex]\( 135 \)[/tex]
2. [tex]\( 362 \)[/tex]
3. [tex]\( 557 \)[/tex]
4. [tex]\( 880 \)[/tex]
5. [tex]\( 746 \)[/tex]
6. [tex]\( 1200 \)[/tex]
7. [tex]\( 505 \)[/tex]
8. [tex]\( 1412 \)[/tex]
9. [tex]\( 8000 \)[/tex]
10. The value is [tex]\( 85 \)[/tex] when reorganized as [tex]\( (52 + 25) + 8 \)[/tex].
