Test your speed and accuracy with this Decimal Operations Ten Minute Challenge, featuring 30 mixed questions on decimals.

Let's solve each of the Decimal Operations Ten Minute Challenge problems step by step. I'll provide the answers and a brief explanation for each.

---

Left Column (1–15)

1) 0.4 + 1.82
Align decimals:
```
0.40
+1.82
------
2.22
```
✔ Answer: 2.22

2) 9.0 - 6.99
Write as 9.00 - 6.99:
```
9.00
-6.99
------
2.01
```
✔ Answer: 2.01

3) 4 × 0.2
4 × 0.2 = 0.8
✔ Answer: 0.8

4) 48 ÷ 0.8
Multiply numerator and denominator by 10 to eliminate decimal:
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 numerator and denominator by 10:
84 ÷ 7 = 12
✔ Answer: 12

8) 1.1 × 5
1.1 × 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
Write as 20.05 - 6.60:
```
20.05
- 6.60
-------
13.45
```
✔ Answer: 13.45

11) 9 × 0.05
9 × 0.05 = 0.45
✔ Answer: 0.45

12) 3.2 ÷ 4
3.2 ÷ 4 = 0.8
✔ Answer: 0.8

13) 0.02 - 0.003
Write as 0.020 - 0.003 = 0.017
✔ Answer: 0.017

14) 17.9 + 19.16
Write 17.9 as 17.90:
```
17.90
+19.16
-------
37.06
```
✔ Answer: 37.06

15) 0.5 × 0.8
Multiply: 5 × 8 = 40 → two decimal places → 0.40
✔ Answer: 0.4

---

Right Column (16–30)

16) 7.2 + 10.09
Write 7.2 as 7.20:
```
7.20
+10.09
-------
17.29
```
✔ Answer: 17.29

17) 100 - 25.46
Write as 100.00 - 25.46:
```
100.00
-25.46
-------
74.54
```
✔ Answer: 74.54

18) 0.6 × 0.3
6 × 3 = 18 → two decimal places → 0.18
✔ Answer: 0.18

19) 5.4 ÷ 9
5.4 ÷ 9 = 0.6
✔ Answer: 0.6

20) 2.64 + 7.8
Write 7.8 as 7.80:
```
2.64
+7.80
-------
10.44
```
✔ Answer: 10.44

21) 65.8 - 20.06
Write 65.8 as 65.80:
```
65.80
-20.06
-------
45.74
```
✔ Answer: 45.74

22) 0.56 ÷ 8
0.56 ÷ 8 = 0.07
✔ Answer: 0.07

23) 2.5 × 7
2.5 × 7 = 17.5
✔ Answer: 17.5

24) 88.44 + 10.88
```
88.44
+10.88
-------
99.32
```
✔ Answer: 99.32

25) 0.15 × 4
0.15 × 4 = 0.60 → 0.6
✔ Answer: 0.6

26) 0.13 × 0.02
13 × 2 = 26 → four decimal places → 0.0026
✔ Answer: 0.0026

27) 10.8 ÷ 0.9
Multiply numerator and denominator by 10:
108 ÷ 9 = 12
✔ Answer: 12

28) 12.05 - 3.007
Write 12.05 as 12.050:
```
12.050
-3.007
-------
9.043
```
✔ Answer: 9.043

29) 0.18 ÷ 0.3
Multiply numerator and denominator by 10:
1.8 ÷ 3 = 0.6
✔ Answer: 0.6

30) 0.7²
0.7 × 0.7 = 0.49
✔ Answer: 0.49

---

✔ Final Answers:

| # | Answer |
|---|--------|
| 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 |

---

✔ All solved! This is a great practice for decimal operations — addition, subtraction, multiplication, division, and powers. Let me know if you'd like a printable version or explanations in another format!