Let's solve each of the 3-digit by 3-digit multiplication problems on the grid. I'll walk through each one step-by-step using the standard multiplication algorithm, and show how to fill in the grid properly.
---
Problem 1: 420 × 389
We’ll multiply:
```
420
× 389
------
```
Break it down:
- 420 × 9 = 3780
- 420 × 80 = 33,600
- 420 × 300 = 126,000
Now add them:
```
3780
33600
+126000
-------
163380
```
✔ Answer: 163,380
---
Problem 2: 833 × 849
```
833
× 849
------
```
Break it down:
- 833 × 9 = 7,497
- 833 × 40 = 33,320
- 833 × 800 = 666,400
Add:
```
7497
33320
+666400
-------
707,217
```
✔ Answer: 707,217
---
Problem 3: 687 × 599
```
687
× 599
------
```
Note: 599 = 600 - 1 → use distributive property:
687 × 599 = 687 × (600 - 1) = 687×600 - 687
- 687 × 600 = 412,200
- Subtract 687 → 412,200 - 687 = 411,513
✔ Answer: 411,513
---
Problem 4: 774 × 483
```
774
× 483
------
```
Break down:
- 774 × 3 = 2,322
- 774 × 80 = 61,920
- 774 × 400 = 309,600
Add:
```
2322
61920
+309600
-------
373,842
```
✔ Answer: 373,842
---
Problem 5: 383 × 775
```
383
× 775
------
```
Break down:
- 383 × 5 = 1,915
- 383 × 70 = 26,810
- 383 × 700 = 268,100
Add:
```
1915
26810
+268100
-------
296,825
```
✔ Answer: 296,825
---
Problem 6: 155 × 330
Note: 330 ends in zero → simplify.
155 × 330 = 155 × 33 × 10
First: 155 × 33
- 155 × 3 = 465
- 155 × 30 = 4,650
- Total: 465 + 4,650 = 5,115
Then ×10 → 51,150
✔ Answer: 51,150
---
Problem 7: 402 × 957
```
402
× 957
------
```
Break down:
- 402 × 7 = 2,814
- 402 × 50 = 20,100
- 402 × 900 = 361,800
Add:
```
2814
20100
+361800
-------
384,714
```
✔ Answer: 384,714
---
Problem 8: 946 × 556
```
946
× 556
------
```
Break down:
- 946 × 6 = 5,676
- 946 × 50 = 47,300
- 946 × 500 = 473,000
Add:
```
5676
47300
+473000
-------
525,976
```
✔ Answer: 525,976
---
Problem 9: 471 × 918
```
471
× 918
------
```
Break down:
- 471 × 8 = 3,768
- 471 × 10 = 4,710
- 471 × 900 = 423,900
Wait — better to do:
918 = 900 + 10 + 8
So:
- 471 × 8 = 3,768
- 471 × 10 = 4,710
- 471 × 900 = 423,900
Add:
```
3768
4710
+423900
-------
432,378
```
✔ Answer: 432,378
---
✔ Final Answers:
| Problem | Answer |
|--------|--------------|
| 1 | 163,380 |
| 2 | 707,217 |
| 3 | 411,513 |
| 4 | 373,842 |
| 5 | 296,825 |
| 6 | 51,150 |
| 7 | 384,714 |
| 8 | 525,976 |
| 9 | 432,378 |
---
📌 How to Use the Grid:
Each grid has rows for:
- The multiplicand (top number)
- The multiplier (bottom number)
- Partial products (one row per digit of the multiplier)
- Final sum at the bottom
You align digits to the right and carry over as needed. The grid helps avoid misalignment.
For example, in 420 × 389:
```
4 2 0
× 3 8 9
-------
3 7 8 0 ← 420 × 9
3 3 6 0 0 ← 420 × 80
1 2 6 0 0 0 ← 420 × 300
------------
1 6 3 3 8 0
```
Just write each partial product in its own row, shifted left appropriately, then add.
Let me know if you'd like a visual version or printable solution!
Parent Tip: Review the logic above to help your child master the concept of 3 digit multiplication worksheet grade 3.
