Let's solve each problem using the
Box Method (also known as the Area Model) for
2-digit by 2-digit multiplication. This method breaks down each number into tens and ones, multiplies each part, and then adds the results.
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🔷 Problem 1: 27 × 33 = 891
✔ Already solved as an example.
We break:
- 27 → 20 + 7
- 33 → 30 + 3
| | 20 | 7 |
|-------|------|------|
|
30 | 600 | 210 |
|
3 | 60 | 21 |
Now add:
- 600 + 210 = 810
- 60 + 21 = 81
- Total: 810 + 81 =
891
✔️ Correct!
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🔷 Problem 2: 45 × 27
Break:
- 45 → 40 + 5
- 27 → 20 + 7
Set up the box:
| | 40 | 5 |
|-------|------|------|
|
20 | 800 | 100 |
|
7 | 280 | 35 |
Now calculate:
- 40 × 20 = 800
- 5 × 20 = 100
- 40 × 7 = 280
- 5 × 7 = 35
Add:
- 800 + 100 = 900
- 280 + 35 = 315
- Total: 900 + 315 =
1,215
✔ Answer:
1,215
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🔷 Problem 3: 39 × 26
Break:
- 39 → 30 + 9
- 26 → 20 + 6
| | 30 | 9 |
|-------|------|------|
|
20 | 600 | 180 |
|
6 | 180 | 54 |
Calculate:
- 30 × 20 = 600
- 9 × 20 = 180
- 30 × 6 = 180
- 9 × 6 = 54
Add:
- 600 + 180 = 780
- 180 + 54 = 234
- Total: 780 + 234 =
1,014
✔ Answer:
1,014
---
🔷 Problem 4: 39 × 18
Break:
- 39 → 30 + 9
- 18 → 10 + 8
| | 30 | 9 |
|-------|------|------|
|
10 | 300 | 90 |
|
8 | 240 | 72 |
Calculate:
- 30 × 10 = 300
- 9 × 10 = 90
- 30 × 8 = 240
- 9 × 8 = 72
Add:
- 300 + 90 = 390
- 240 + 72 = 312
- Total: 390 + 312 =
702
✔ Answer:
702
---
🔷 Problem 5: 77 × 82
Break:
- 77 → 70 + 7
- 82 → 80 + 2
| | 70 | 7 |
|-------|------|------|
|
80 | 5600 | 560 |
|
2 | 140 | 14 |
Calculate:
- 70 × 80 = 5,600
- 7 × 80 = 560
- 70 × 2 = 140
- 7 × 2 = 14
Add:
- 5,600 + 560 = 6,160
- 140 + 14 = 154
- Total: 6,160 + 154 =
6,314
✔ Answer:
6,314
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🔷 Problem 6: 27 × 92
Break:
- 27 → 20 + 7
- 92 → 90 + 2
| | 20 | 7 |
|-------|------|------|
|
90 | 1800 | 630 |
|
2 | 40 | 14 |
Calculate:
- 20 × 90 = 1,800
- 7 × 90 = 630
- 20 × 2 = 40
- 7 × 2 = 14
Add:
- 1,800 + 630 = 2,430
- 40 + 14 = 54
- Total: 2,430 + 54 =
2,484
✔ Answer:
2,484
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✔ Final Answers:
1. 27 × 33 =
891
2. 45 × 27 =
1,215
3. 39 × 26 =
1,014
4. 39 × 18 =
702
5. 77 × 82 =
6,314
6. 27 × 92 =
2,484
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📝 Summary of Box Method Steps:
1. Break both numbers into tens and ones.
2. Set up a 2×2 grid.
3. Multiply each part (top-left, top-right, bottom-left, bottom-right).
4. Add all four products to get the final answer.
This method helps visualize how multiplication works and is especially useful for understanding place value.
Let me know if you'd like this formatted as a filled-in worksheet!
Parent Tip: Review the logic above to help your child master the concept of box method multiplication worksheet.
