Multiplying Decimals Worksheets - Math Monks - Free Printable

Let’s solve each multiplication problem step by step. We’ll multiply the numbers as if they were whole numbers first, then count how many decimal places are in both numbers together — that’s how many decimal places our answer will have.

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Problem 1: 7.4 × 2.3

- Ignore decimals: 74 × 23 = ?
- 74 × 20 = 1480
- 74 × 3 = 222
- Total = 1480 + 222 = 1702
- Decimal places: 7.4 has 1, 2.3 has 1 → total 2 decimal places
- So, 1702 becomes 17.02

✔ Answer: 17.02

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Problem 2: 2.88 × 16.33

- Ignore decimals: 288 × 1633
Let’s break it down:
- 288 × 1600 = 288 × 16 × 100 = (288×10=2880; 288×6=1728 → 2880+1728=4608) ×100 = 460,800
- 288 × 33 = 288×30 + 288×3 = 8640 + 864 = 9504
- Total = 460,800 + 9,504 = 470,304
- Decimal places: 2.88 has 2, 16.33 has 2 → total 4 decimal places
- So, 470304 becomes 47.0304

✔ Answer: 47.0304

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Problem 3: 15 × 0.73

- Ignore decimals: 15 × 73 = ?
- 15 × 70 = 1050
- 15 × 3 = 45
- Total = 1050 + 45 = 1095
- Decimal places: 15 has 0, 0.73 has 2 → total 2 decimal places
- So, 1095 becomes 10.95

✔ Answer: 10.95

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Problem 4: 0.89 × 0.53

- Ignore decimals: 89 × 53
- 89 × 50 = 4450
- 89 × 3 = 267
- Total = 4450 + 267 = 4717
- Decimal places: 0.89 has 2, 0.53 has 2 → total 4 decimal places
- So, 4717 becomes 0.4717

✔ Answer: 0.4717

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Problem 5: 82 × 0.86

- Ignore decimals: 82 × 86
- 80 × 86 = 6880
- 2 × 86 = 172
- Total = 6880 + 172 = 7052
- Decimal places: 82 has 0, 0.86 has 2 → total 2 decimal places
- So, 7052 becomes 70.52

✔ Answer: 70.52

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Problem 6: 0.133 × 0.478

- Ignore decimals: 133 × 478
Let’s compute:
- 133 × 400 = 53,200
- 133 × 70 = 9,310
- 133 × 8 = 1,064
- Total = 53,200 + 9,310 = 62,510 + 1,064 = 63,574
- Decimal places: 0.133 has 3, 0.478 has 3 → total 6 decimal places
- So, 63574 becomes 0.063574 (we need to add leading zeros to make 6 decimal places)

✔ Answer: 0.063574

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Problem 7: 39.04 × 6.86

- Ignore decimals: 3904 × 686
Break it down:
- 3904 × 600 = 2,342,400
- 3904 × 80 = 312,320
- 3904 × 6 = 23,424
- Add them:
2,342,400
+ 312,320 = 2,654,720
+ 23,424 = 2,678,144
- Decimal places: 39.04 has 2, 6.86 has 2 → total 4 decimal places
- So, 2678144 becomes 267.8144

✔ Answer: 267.8144

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Problem 8: 22.29 × 19.31

- Ignore decimals: 2229 × 1931
This is big — let’s do it carefully:

We can use:
2229 × 1931 = 2229 × (2000 - 69) = 2229×2000 - 2229×69

But maybe easier to do direct multiplication:

Actually, let’s do:

2229 × 1931

Break 1931 into 1000 + 900 + 30 + 1

- 2229 × 1000 = 2,229,000
- 2229 × 900 = 2,006,100
- 2229 × 30 = 66,870
- 2229 × 1 = 2,229

Now add:

2,229,000
+2,006,100 = 4,235,100
+66,870 = 4,301,970
+2,229 = 4,304,199

Wait — let me double-check with another method or calculator-style:

Actually, better to do:

2229 × 1931

Use standard multiplication:

2229
× 1931
--------
2229 ← ×1
66870 ← ×30
2006100 ← ×900
2229000 ← ×1000
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Add:

Start from right:

Units: 9
Tens: 2+7=9
Hundreds: 2+8+1=11 → write 1, carry 1
Thousands: 2+6+6+0 +1(carry)=15 → write 5, carry 1
Ten thousands: 2+0+1+9 +1=13 → write 3, carry 1
Hundred thousands: 2+0+0+2 +1=5
Millions: 2

Wait — this is getting messy. Let me just calculate numerically:

2229 × 1931 = ?

Let me compute 2229 × 1900 = 2229 × 19 × 100

2229 × 19:

2229 × 20 = 44,580 minus 2229 = 44,580 - 2,229 = 42,351

Then ×100 = 4,235,100

Now 2229 × 31 = ?

2229 × 30 = 66,870
2229 × 1 = 2,229
Total = 66,870 + 2,229 = 69,099

Now total = 4,235,100 + 69,099 = 4,304,199

Yes! Same as before.

Decimal places: 22.29 has 2, 19.31 has 2 → total 4 decimal places

So, 4304199 becomes 430.4199

✔ Answer: 430.4199

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Problem 9: 0.007 × 1.7

- Ignore decimals: 7 × 17 = 119
- Decimal places: 0.007 has 3, 1.7 has 1 → total 4 decimal places
- So, 119 becomes 0.0119 (add leading zero to make 4 decimal places)

✔ Answer: 0.0119

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Final Answer:
1. 17.02
2. 47.0304
3. 10.95
4. 0.4717
5. 70.52
6. 0.063574
7. 267.8144
8. 430.4199
9. 0.0119