Let's solve each multiplication problem step by step using the
standard algorithm (also known as long multiplication). The format of the worksheet shows that we need to:
1. Multiply the top number by the ones digit of the bottom number.
2. Multiply the top number by the tens digit of the bottom number (and shift one place to the left).
3. Add the two partial products.
We'll go through each problem and fill in the blanks accordingly.
---
🔹 Problem 1: $ 21 \times 34 $
```
21
× 34
----
84 ← 21 × 4
630 ← 21 × 30 (shifted left)
----
714
```
So:
- First line: `84`
- Second line: `630` (with a zero placeholder)
- Final sum: `714`
✔ Answer:
714
---
🔹 Problem 2: $ 12 \times 43 $
```
12
× 43
----
36 ← 12 × 3
480 ← 12 × 40
----
516
```
✔ Answer:
516
---
🔹 Problem 3: $ 12 \times 32 $
```
12
× 32
----
24 ← 12 × 2
360 ← 12 × 30
----
384
```
✔ Answer:
384
---
🔹 Problem 4: $ 21 \times 23 $
```
21
× 23
----
63 ← 21 × 3
420 ← 21 × 20
----
483
```
✔ Answer:
483
---
🔹 Problem 5: $ 31 \times 12 $
```
31
× 12
----
62 ← 31 × 2
310 ← 31 × 10
----
372
```
✔ Answer:
372
---
🔹 Problem 6: $ 13 \times 21 $
```
13
× 21
----
13 ← 13 × 1
260 ← 13 × 20
----
273
```
✔ Answer:
273
---
🔹 Problem 7: $ 22 \times 11 $
```
22
× 11
----
22 ← 22 × 1
220 ← 22 × 10
----
242
```
✔ Answer:
242
---
🔹 Problem 8: $ 12 \times 21 $
```
12
× 21
----
12 ← 12 × 1
240 ← 12 × 20
----
252
```
✔ Answer:
252
---
🔹 Problem 9: $ 32 \times 12 $
```
32
× 12
----
64 ← 32 × 2
320 ← 32 × 10
----
384
```
✔ Answer:
384
---
##
✔ Final Answers (Filling in the blanks):
| Problem | Partial Product 1 | Partial Product 2 | Sum |
|--------|-------------------|-------------------|-----|
| 21 × 34 | 84 | 630 | 714 |
| 12 × 43 | 36 | 480 | 516 |
| 12 × 32 | 24 | 360 | 384 |
| 21 × 23 | 63 | 420 | 483 |
| 31 × 12 | 62 | 310 | 372 |
| 13 × 21 | 13 | 260 | 273 |
| 22 × 11 | 22 | 220 | 242 |
| 12 × 21 | 12 | 240 | 252 |
| 32 × 12 | 64 | 320 | 384 |
---
📝 Instructions for Filling the Worksheet:
For each box, write:
1. The first partial product (e.g., 84 for 21×34) under the multiplication.
2. The second partial product (e.g., 630), shifted left, with a zero already provided (so you just write the number without the zero).
3. Then add them to get the final answer.
> Note: The "+ ___ 0" line is meant for the second partial product (tens place), so you write the number
without the zero — the grid already has it.
---
✔ Example Fill-in (Top Left Box):
```
21
×34
----
84
+630
----
714
```
Repeat similarly for all others.
Let me know if you'd like a printable version or PDF of the filled worksheet!
Parent Tip: Review the logic above to help your child master the concept of column addition worksheet on squared paper.
