Here are the solutions to all 30 decimal operations problems, with step-by-step explanations for each.
---
1) 0.4 + 1.82 =
Align decimals:
```
0.40
+ 1.82
------
2.22
```
✔ Answer: 2.22
---
2) 9.0 - 6.99 =
Align decimals:
```
9.00
- 6.99
------
2.01
```
✔ Answer: 2.01
---
3) 4 × 0.2 =
Multiply as whole numbers: 4 × 2 = 8
Count decimal places: 0.2 has 1 decimal place → answer has 1 decimal place.
✔ Answer: 0.8
---
4) 48 ÷ 0.8 =
Multiply numerator and denominator by 10 to eliminate decimal:
48 ÷ 0.8 = 480 ÷ 8 = 60
✔ Answer: 60
---
5) 3.5 + 6.7 =
```
3.5
+ 6.7
-----
10.2
```
✔ Answer: 10.2
---
6) 19.1 - 5.3 =
```
19.1
- 5.3
-----
13.8
```
✔ Answer: 13.8
---
7) 8.4 ÷ 0.7 =
Multiply both by 10: 84 ÷ 7 = 12
✔ Answer: 12
---
8) 1.1 × 5 =
1.1 × 5 = (1 × 5) + (0.1 × 5) = 5 + 0.5 = 5.5
✔ Answer: 5.5
---
9) 12.3 + 15.9 =
```
12.3
+15.9
-----
28.2
```
✔ Answer: 28.2
---
10) 20.05 - 6.6 =
Align decimals:
```
20.05
- 6.60
-------
13.45
```
✔ Answer: 13.45
---
11) 9 × 0.05 =
9 × 5 = 45 → 0.05 has 2 decimal places → 0.45
✔ Answer: 0.45
---
12) 3.2 ÷ 4 =
3.2 ÷ 4 = 32 ÷ 40 = 0.8
✔ Answer: 0.8
---
13) 0.02 - 0.003 =
Align decimals:
```
0.020
-0.003
------
0.017
```
✔ Answer: 0.017
---
14) 17.9 + 19.16 =
Align decimals:
```
17.90
+19.16
-------
37.06
```
✔ Answer: 37.06
---
15) 0.5 × 0.8 =
5 × 8 = 40 → total 2 decimal places → 0.40 → 0.4
✔ Answer: 0.4
---
16) 7.2 + 10.09 =
Align decimals:
```
7.20
+10.09
-------
17.29
```
✔ Answer: 17.29
---
17) 100 - 25.46 =
```
100.00
-25.46
-------
74.54
```
✔ Answer: 74.54
---
18) 0.6 × 0.3 =
6 × 3 = 18 → 2 decimal places → 0.18
✔ Answer: 0.18
---
19) 5.4 ÷ 9 =
5.4 ÷ 9 = 54 ÷ 90 = 0.6
✔ Answer: 0.6
---
20) 2.64 + 7.8 =
Align decimals:
```
2.64
+ 7.80
-------
10.44
```
✔ Answer: 10.44
---
21) 65.8 - 20.06 =
Align decimals:
```
65.80
-20.06
-------
45.74
```
✔ Answer: 45.74
---
22) 0.56 ÷ 8 =
56 ÷ 8 = 7 → 0.56 has 2 decimal places → 0.07
✔ Answer: 0.07
---
23) 2.5 × 7 =
2.5 × 7 = (2 × 7) + (0.5 × 7) = 14 + 3.5 = 17.5
✔ Answer: 17.5
---
24) 88.44 + 10.88 =
```
88.44
+10.88
-------
99.32
```
✔ Answer: 99.32
---
25) 0.15 × 4 =
15 × 4 = 60 → 2 decimal places → 0.60 → 0.6
✔ Answer: 0.6
---
26) 0.13 × 0.02 =
13 × 2 = 26 → total 3 decimal places (2+1) → 0.0026
✔ Answer: 0.0026
---
27) 10.8 ÷ 0.9 =
Multiply both by 10: 108 ÷ 9 = 12
✔ Answer: 12
---
28) 12.05 - 3.007 =
Align decimals:
```
12.050
- 3.007
--------
9.043
```
✔ Answer: 9.043
---
29) 0.18 ÷ 0.3 =
Multiply both by 10: 1.8 ÷ 3 = 0.6
✔ Answer: 0.6
---
30) 0.7² =
0.7 × 0.7 = 49 → 2 decimal places → 0.49
✔ Answer: 0.49
---
##
✔ Final Answer Key:
1) 2.22
2) 2.01
3) 0.8
4) 60
5) 10.2
6) 13.8
7) 12
8) 5.5
9) 28.2
10) 13.45
11) 0.45
12) 0.8
13) 0.017
14) 37.06
15) 0.4
16) 17.29
17) 74.54
18) 0.18
19) 0.6
20) 10.44
21) 45.74
22) 0.07
23) 17.5
24) 99.32
25) 0.6
26) 0.0026
27) 12
28) 9.043
29) 0.6
30) 0.49
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Parent Tip: Review the logic above to help your child master the concept of decimal worksheet pdf.
