Multiplying Decimals (A) Worksheet | PDF Printable Number ... - Free Printable

Let's solve each section of the worksheet step by step and explain the reasoning.

---

Section A: Quick Decimal Multiplication & Division

These problems involve multiplying or dividing decimals by 10.

Rules to remember:
- When you multiply a number by 10, move the decimal point one place to the right.
- When you divide a number by 10, move the decimal point one place to the left.

1. 0.6 × 10
→ Move decimal one place right: 6.0 → 6

2. 91 ÷ 10
→ Move decimal one place left: 9.1

3. 40.8 × 10
→ Move decimal one place right: 408

4. 875 ÷ 10
→ Move decimal one place left: 87.5

✔ Answers:
- 0.6 × 10 = 6
- 91 ÷ 10 = 9.1
- 40.8 × 10 = 408
- 875 ÷ 10 = 87.5

---

Section B: Multiply Whole Numbers First, Then Use for Decimals

We are told to first multiply whole numbers, then use that to help with decimal multiplication.

#### Whole Number Multiplications (1–5):

1) 27 × 3 = 81
2) 84 × 5 = 420
3) 62 × 9 = 558
4) 108 × 6 = 648
5) 639 × 8 = 5112

Now use these to find the decimal products:

6) 2.7 × 3
→ Think of 27 × 3 = 81 → but 2.7 is 27 ÷ 10 → so result is 81 ÷ 10 = 8.1

7) 8.4 × 5
→ 84 × 5 = 420 → 8.4 is 84 ÷ 10 → so result = 420 ÷ 10 = 42.0 → 42

8) 62 × 0.9
→ 62 × 9 = 558 → 0.9 is 9 ÷ 10 → so 558 ÷ 10 = 55.8

9) 108 × 0.6
→ 108 × 6 = 648 → 0.6 is 6 ÷ 10 → so 648 ÷ 10 = 64.8

10) 63.9 × 8
→ 639 × 8 = 5112 → 63.9 is 639 ÷ 10 → so 5112 ÷ 10 = 511.2

✔ Answers:
- 6) 8.1
- 7) 42
- 8) 55.8
- 9) 64.8
- 10) 511.2

---

Section C: Direct Decimal Multiplication

Multiply decimals directly.

Remember: Multiply as if they were whole numbers, then count total decimal places in factors and place decimal in answer accordingly.

1) 3 × 0.4
→ 3 × 4 = 12 → 0.4 has 1 decimal place → 1.2

2) 9 × 0.7
→ 9 × 7 = 63 → 1 decimal place → 6.3

3) 8 × 0.2
→ 8 × 2 = 16 → 1 decimal place → 1.6

4) 0.6 × 4
→ 6 × 4 = 24 → 1 decimal place → 2.4

5) 4 × 1.9
→ 4 × 19 = 76 → 1 decimal place → 7.6

6) 5 × 2.7
→ 5 × 27 = 135 → 1 decimal place → 13.5

7) 6 × 3.8
→ 6 × 38 = 228 → 1 decimal place → 22.8

8) 9.3 × 2
→ 93 × 2 = 186 → 1 decimal place → 18.6

9) 7 × 16.2
→ 7 × 162 = 1134 → 1 decimal place → 113.4

10) 13.9 × 8
→ 139 × 8 = 1112 → 1 decimal place → 111.2

11) 4 × 57.4
→ 4 × 574 = 2296 → 1 decimal place → 229.6

12) 36.4 × 7
→ 364 × 7 = 2548 → 1 decimal place → 254.8

✔ Answers:
1) 1.2
2) 6.3
3) 1.6
4) 2.4
5) 7.6
6) 13.5
7) 22.8
8) 18.6
9) 113.4
10) 111.2
11) 229.6
12) 254.8

---

Section D: Word Problems

#### 1) Daniel wants to lose 1.2 kg per week for 9 weeks. Total weight loss?

Multiply:
1.2 × 9

Break it down:
- 1 × 9 = 9
- 0.2 × 9 = 1.8
- Add: 9 + 1.8 = 10.8 kg

✔ Answer: Daniel wants to lose 10.8 kg in total.

---

#### 2) Anita has $1.55. Apples cost $0.30 each.

##### a) Does she have enough to buy 6 apples?

Cost of 6 apples:
6 × 0.30 = ?

6 × 30 = 180 → 180 cents = $1.80

But Anita has only $1.55 → No, she doesn't have enough.

✔ Answer: No, she does not have enough money.

##### b) How much more does she need to buy 10 apples?

Cost of 10 apples:
10 × 0.30 = $3.00

She has $1.55

Amount needed:
3.00 – 1.55 = $1.45

✔ Answer: She needs $1.45 more.

---

✔ Final Answers Summary

---

Section A

- 0.6 × 10 = 6
- 91 ÷ 10 = 9.1
- 40.8 × 10 = 408
- 875 ÷ 10 = 87.5

---

Section B

1) 27 × 3 = 81
2) 84 × 5 = 420
3) 62 × 9 = 558
4) 108 × 6 = 648
5) 639 × 8 = 5112
6) 2.7 × 3 = 8.1
7) 8.4 × 5 = 42
8) 62 × 0.9 = 55.8
9) 108 × 0.6 = 64.8
10) 63.9 × 8 = 511.2

---

Section C

1) 3 × 0.4 = 1.2
2) 9 × 0.7 = 6.3
3) 8 × 0.2 = 1.6
4) 0.6 × 4 = 2.4
5) 4 × 1.9 = 7.6
6) 5 × 2.7 = 13.5
7) 6 × 3.8 = 22.8
8) 9.3 × 2 = 18.6
9) 7 × 16.2 = 113.4
10) 13.9 × 8 = 111.2
11) 4 × 57.4 = 229.6
12) 36.4 × 7 = 254.8

---

Section D

1) Total weight loss = 10.8 kg
2) a) No, she does not have enough.
b) She needs $1.45 more.

---

Let me know if you'd like this formatted as a printable answer key!