Adding Decimals Worksheet 5th Grade - 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 the total decimal places in both numbers and put the decimal point in the answer accordingly.

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Problem 1: 655.25 × 12.02

Step 1: Ignore decimals → 65525 × 1202
But that’s big — let’s break it down:

Actually, better to do:

655.25 has 2 decimal places
12.02 has 2 decimal places
Total = 4 decimal places in final answer

Now multiply 65525 × 1202:

First, 65525 × 1000 = 65,525,000
65525 × 200 = 13,105,000
65525 × 2 = 131,050

Add them:
65,525,000 + 13,105,000 = 78,630,000
+ 131,050 = 78,761,050

Now move decimal 4 places left → 7876.1050 → 7876.105

Wait — let me double-check with calculator-style steps:

Actually, easier way:

655.25 × 12.02
= (655.25 × 12) + (655.25 × 0.02)

655.25 × 12 = 655.25 × 10 + 655.25 × 2 = 6552.5 + 1310.5 = 7863.0
655.25 × 0.02 = 13.105

Add: 7863.0 + 13.105 = 7876.105

✔ Correct.

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Problem 2: 465.2 × 10.20

Note: 10.20 is same as 10.2 (trailing zero doesn’t change value)

465.2 has 1 decimal place
10.20 has 2 decimal places → but since trailing zero, we can treat as 10.2 → 1 decimal? Wait no — 10.20 is two decimal places numerically, even if last digit is zero.

So total decimal places = 1 + 2 = 3

Multiply 4652 × 1020 (ignore decimals)

Easier: 465.2 × 10.2

Break it:

465.2 × 10 = 4652
465.2 × 0.2 = 93.04
Add: 4652 + 93.04 = 4745.04

Wait — but we said 3 decimal places? Let’s check:

Original: 465.2 (1 decimal) × 10.20 (2 decimals) → 3 decimals

But 4745.04 has only 2 decimals? That means I made a mistake.

Wait — 10.20 is actually 10.2, which is one decimal? No — 10.20 written with two digits after decimal counts as two decimal places for calculation purposes.

But mathematically, 10.20 = 10.2, so multiplying by 10.20 is same as 10.2.

Let’s compute exactly:

465.2 × 10.20 = ?

Do 4652 × 1020 = ? Then divide by 1000 (because 465.2 = 4652/10, 10.20 = 1020/100 → total denominator 10×100=1000)

4652 × 1020:

4652 × 1000 = 4,652,000
4652 × 20 = 93,040
Total = 4,745,040

Divide by 1000 → 4745.040 → which is 4745.04

Yes, because trailing zero after decimal doesn’t matter. So answer is 4745.04

But according to decimal places: 1 + 2 = 3, so should be 4745.040 — but we write as 4745.04

It’s fine.

✔ Final: 4745.04

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Problem 3: 536.24 × 12.24

Both have 2 decimal places → total 4 decimal places

Multiply 53624 × 1224

This is big — let’s break it:

536.24 × 12.24 = ?

Use:

536.24 × 12 = 536.24 × 10 + 536.24 × 2 = 5362.4 + 1072.48 = 6434.88
536.24 × 0.24 = ?

First, 536.24 × 0.2 = 107.248
536.24 × 0.04 = 21.4496
Add: 107.248 + 21.4496 = 128.6976

Now add to previous: 6434.88 + 128.6976 = 6563.5776

✔ Answer: 6563.5776

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Problem 4: 351.12 × 150

150 is whole number → 0 decimal places
351.12 has 2 decimal places → answer has 2 decimal places

Multiply 35112 × 150

35112 × 100 = 3,511,200
35112 × 50 = 1,755,600
Total = 5,266,800

Now divide by 100 (since 351.12 = 35112/100) → 52,668.00

So 52668.00 → or just 52668

But since original had 2 decimals, we keep two: 52668.00

But usually we drop trailing zeros → 52668

Wait — let’s verify:

351.12 × 150 = 351.12 × 100 + 351.12 × 50 = 35112 + 17556 = 52668

Yes → 52668

✔ Final: 52668

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Problem 5: 251.25 × 15.20

251.25 → 2 decimals
15.20 → 2 decimals → total 4 decimals

Multiply 25125 × 1520

Or break:

251.25 × 15 = 251.25 × 10 + 251.25 × 5 = 2512.5 + 1256.25 = 3768.75
251.25 × 0.20 = 50.25

Add: 3768.75 + 50.25 = 3819.00

Wait — that gives 3819.00, but we expected 4 decimal places? Something wrong.

Ah! 15.20 is 15.2, so 251.25 × 15.2

Better:

251.25 × 15.2 = ?

251.25 × 15 = 3768.75
251.25 × 0.2 = 50.25
Sum: 3819.00

But 251.25 has 2 decimals, 15.20 has 2 decimals → product should have 4 decimals? But 3819.00 has only 2.

Why? Because 15.20 is actually 1520/100, 251.25 is 25125/100 → product = (25125 × 1520) / 10000

Compute 25125 × 1520:

25125 × 1500 = 25125 × 1000 + 25125 × 500 = 25,125,000 + 12,562,500 = 37,687,500
25125 × 20 = 502,500
Total = 38,190,000

Divide by 10000 → 3819.0000 → 3819.00

So yes, it’s correct. The extra decimals are zeros.

✔ Final: 3819.00 or 3819

We’ll write as 3819

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Problem 6: 520.26 × 50.26

Both have 2 decimals → total 4 decimals

Multiply 52026 × 5026

Too big — use breakdown:

520.26 × 50 = 26,013
520.26 × 0.26 = ?

520.26 × 0.2 = 104.052
520.26 × 0.06 = 31.2156
Add: 104.052 + 31.2156 = 135.2676

Now total: 26,013 + 135.2676 = 26,148.2676

✔ Answer: 26148.2676

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Problem 7: 231.20 × 10

Multiplying by 10 → move decimal one place right

231.20 → becomes 2312.0

✔ 2312

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Problem 8: 565.26 × 100

Move decimal two places right → 56526

✔ 56526

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Problem 9: 125.24 × 10

Move decimal one place right → 1252.4

✔ 1252.4

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Problem 10: 145.28 × 15.25

145.28 → 2 decimals
15.25 → 2 decimals → total 4 decimals

Break:

145.28 × 15 = 145.28 × 10 + 145.28 × 5 = 1452.8 + 726.4 = 2179.2
145.28 × 0.25 = ?

0.25 is quarter → 145.28 ÷ 4 = 36.32

Add: 2179.2 + 36.32 = 2215.52

Wait — but we need 4 decimal places? This has only 2.

Mistake again.

Actually: 145.28 × 15.25

Better: 14528 × 1525 / 10000

Or:

145.28 × 15.25 = 145.28 × (15 + 0.25) = as above 2179.2 + 36.32 = 2215.52

But let’s compute exactly:

145.28 × 15.25

Do 14528 × 1525 = ?

Easier: 145.28 × 15.25

Use:

145.28 × 15 = 2179.2
145.28 × 0.25 = 36.32
Sum: 2215.52

But 145.28 has 2 decimals, 15.25 has 2 → product should have 4 decimals? Why only 2?

Because 2215.52 is actually 2215.5200 — the other decimals are zero.

Check with another method:

145.28 × 15.25 = ?

Calculate 14528 × 1525 = ?

14528 × 1500 = 21,792,000
14528 × 25 = 363,200
Total = 22,155,200

Divide by 10000 (since 145.28 = 14528/100, 15.25=1525/100 → 100*100=10000) → 2215.5200

So 2215.52

✔ Final: 2215.52

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Problem 11: 150.29 × 100

Move decimal two places right → 15029

✔ 15029

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Problem 12: 652.26 × 1.60

652.26 → 2 decimals
1.60 → 2 decimals → total 4 decimals

But 1.60 = 1.6

So 652.26 × 1.6

Break:

652.26 × 1 = 652.26
652.26 × 0.6 = 391.356
Add: 652.26 + 391.356 = 1043.616

Now, since we treated 1.60 as 1.6, but originally 2 decimals each → should be 4 decimals? 1043.616 has 3.

Wait — 652.26 × 1.60 = ?

65226 × 160 / 10000

65226 × 160 = 65226 × 100 + 65226 × 60 = 6,522,600 + 3,913,560 = 10,436,160

Divide by 10000 → 1043.6160 → 1043.616

✔ Final: 1043.616

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Now compiling all answers:

1. 655.25 × 12.02 = 7876.105
2. 465.2 × 10.20 = 4745.04
3. 536.24 × 12.24 = 6563.5776
4. 351.12 × 150 = 52668
5. 251.25 × 15.20 = 3819
6. 520.26 × 50.26 = 26148.2676
7. 231.20 × 10 = 2312
8. 565.26 × 100 = 56526
9. 125.24 × 10 = 1252.4
10. 145.28 × 15.25 = 2215.52
11. 150.29 × 100 = 15029
12. 652.26 × 1.60 = 1043.616

Final Answer:
7876.105, 4745.04, 6563.5776, 52668, 3819, 26148.2676, 2312, 56526, 1252.4, 2215.52, 15029, 1043.616