Q1.
Check if Asma's solution is correct. Asma's solution for 46 × 59: 2,000 + 300 + 360 + 54 = 2,714. If correct, explain why. If incorrect, identify the error and correct the solution.
Answer
Asma is correct. 46 × 59 = 2,714.
She split both numbers into place values and wrote all four pieces. Let us name them.
| Her line | Where it comes from | Check |
|---|---|---|
| 2,000 | 50 × 40 | 2,000 ✓ |
| 300 | 50 × 6 | 300 ✓ |
| 360 | 9 × 40 | 360 ✓ |
| 54 | 9 × 6 | 54 ✓ |
2,000 + 300 = 2,300
2,300 + 360 = 2,660
2,660 + 54 = 2,714 ✓
2,300 + 360 = 2,660
2,660 + 54 = 2,714 ✓
Why her solution works: 46 is 40 + 6 and 59 is 50 + 9. Two parts times two parts gives four pieces, and she found all four. None is missing and none is counted twice, so the total must be right.
Check it by a second route: 46 × 59 = 46 × 60 − 46 = 2,760 − 46 = 2,714 ✓