Let's solve each of the multiplication problems on this Kumon worksheet step by step. The task is to multiply a two-digit number by a one-digit number.
---
(1)
43 × 2
Break it down:
- 3 × 2 = 6
- 40 × 2 = 80
- Add: 80 + 6 =
86
✔ Answer:
86 (already filled in)
---
(2)
34 × 2
- 4 × 2 = 8
- 30 × 2 = 60
- Add: 60 + 8 =
68
✔ Answer:
68
So, fill in the box:
```
34
× 2
----
68
```
---
(3)
31 × 2
- 1 × 2 = 2
- 30 × 2 = 60
- Add: 60 + 2 =
62
✔ Answer:
62
Fill in the blank:
```
31
× 2
----
62
```
---
(4)
41 × 2
- 1 × 2 = 2
- 40 × 2 = 80
- Add: 80 + 2 =
82
✔ Answer:
82
```
41
× 2
----
82
```
---
(5)
13 × 2
- 3 × 2 = 6
- 10 × 2 = 20
- Add: 20 + 6 =
26
✔ Answer:
26
```
13
× 2
----
26
```
---
(6)
21 × 2
- 1 × 2 = 2
- 20 × 2 = 40
- Add: 40 + 2 =
42
✔ Answer:
42
```
21
× 2
----
42
```
---
(7)
32 × 2
- 2 × 2 = 4
- 30 × 2 = 60
- Add: 60 + 4 =
64
✔ Answer:
64
```
32
× 2
----
64
```
---
(8)
42 × 2
- 2 × 2 = 4
- 40 × 2 = 80
- Add: 80 + 4 =
84
✔ Answer:
84
```
42
× 2
----
84
```
---
✔ Final Answers:
| Problem | Answer |
|--------|--------|
| (1) | 86 |
| (2) | 68 |
| (3) | 62 |
| (4) | 82 |
| (5) | 26 |
| (6) | 42 |
| (7) | 64 |
| (8) | 84 |
---
🔍 Explanation:
Each problem involves multiplying a two-digit number by 2. You can use the
distributive property:
> (Tens digit × 10 + Units digit) × 2 = (Tens digit × 2) × 10 + (Units digit × 2)
For example:
- 34 × 2 = (30 + 4) × 2 = 30×2 + 4×2 = 60 + 8 = 68
This method helps avoid errors and reinforces understanding.
Also, note the
"Note" section at the bottom showing that:
> 43 + 43 = 86
> 43 × 2 = 86
This illustrates that
multiplying by 2 is the same as adding the number to itself, which is a helpful concept for young learners.
---
Let me know if you'd like a printable version or a PDF with answers filled in!
Parent Tip: Review the logic above to help your child master the concept of kumon maths worksheet.
