Multiplying Decimals Worksheets - Math Monks - Free Printable

Let's solve each of these multiplication problems step by step. The task is to multiply a decimal number with one decimal place (like 1.4, 2.1, etc.) by a single-digit whole number (2, 3, 4, or 5).

🔢 Key Rule:

When multiplying a decimal by a whole number:
- Ignore the decimal point initially and multiply as if both numbers were whole numbers.
- Then count the total number of decimal places in the original numbers (here, only one decimal place).
- Place the decimal point in the answer so that it has the same number of decimal places.

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Let’s go through all 24 problems:

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1) 1.4 × 3
→ 14 × 3 = 42 → 1 decimal place → 4.2

2) 2.1 × 4
→ 21 × 4 = 84 → 1 decimal place → 8.4

3) 4.3 × 2
→ 43 × 2 = 86 → 1 decimal place → 8.6

4) 1.6 × 5
→ 16 × 5 = 80 → 1 decimal place → 8.0 or just 8.0

5) 3.1 × 4
→ 31 × 4 = 124 → 1 decimal place → 12.4

6) 4.3 × 2
→ 43 × 2 = 86 → 1 decimal place → 8.6

7) 3.3 × 3
→ 33 × 3 = 99 → 1 decimal place → 9.9

8) 2.1 × 5
→ 21 × 5 = 105 → 1 decimal place → 10.5

9) 3.4 × 3
→ 34 × 3 = 102 → 1 decimal place → 10.2

10) 3.5 × 5
→ 35 × 5 = 175 → 1 decimal place → 17.5

11) 7.7 × 2
→ 77 × 2 = 154 → 1 decimal place → 15.4

12) 2.8 × 4
→ 28 × 4 = 112 → 1 decimal place → 11.2

13) 3.6 × 4
→ 36 × 4 = 144 → 1 decimal place → 14.4

14) 5.9 × 2
→ 59 × 2 = 118 → 1 decimal place → 11.8

15) 7.7 × 3
→ 77 × 3 = 231 → 1 decimal place → 23.1

16) 6.1 × 4
→ 61 × 4 = 244 → 1 decimal place → 24.4

17) 4.7 × 3
→ 47 × 3 = 141 → 1 decimal place → 14.1

18) 6.3 × 5
→ 63 × 5 = 315 → 1 decimal place → 31.5

19) 9.8 × 2
→ 98 × 2 = 196 → 1 decimal place → 19.6

20) 6.5 × 4
→ 65 × 4 = 260 → 1 decimal place → 26.0 or 26.0

21) 3.6 × 4
→ 36 × 4 = 144 → 1 decimal place → 14.4

22) 6.9 × 2
→ 69 × 2 = 138 → 1 decimal place → 13.8

23) 4.8 × 3
→ 48 × 3 = 144 → 1 decimal place → 14.4

24) 7.4 × 5
→ 74 × 5 = 370 → 1 decimal place → 37.0 or 37.0

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✔ Final Answers:

1) 4.2
2) 8.4
3) 8.6
4) 8.0
5) 12.4
6) 8.6
7) 9.9
8) 10.5
9) 10.2
10) 17.5
11) 15.4
12) 11.2
13) 14.4
14) 11.8
15) 23.1
16) 24.4
17) 14.1
18) 31.5
19) 19.6
20) 26.0
21) 14.4
22) 13.8
23) 14.4
24) 37.0

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📝 Explanation Summary:

- Multiply the numbers as if they were whole numbers.
- Count how many decimal places are in the original decimal (here: always 1).
- Place the decimal point in the product so it has one decimal place.
- This method works because multiplying by a whole number doesn't change the decimal placement logic.

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