The task involves adding and subtracting decimals with regrouping. Let's solve each problem step by step.
---
1. \( 1.5 + 7.7 \)
- Align the decimal points:
```
1.5
+ 7.7
------
9.2
```
-
Result: \( 9.2 \)
---
2. \( 13.9 + 51.58 \)
- Align the decimal points:
```
13.90
+ 51.58
-------
65.48
```
-
Result: \( 65.48 \)
---
3. \( 49.68 - 28.689 \)
- Align the decimal points:
```
49.680
- 28.689
---------
20.991
```
-
Result: \( 20.991 \)
---
4. \( 2.6 + 5.7 \)
- Align the decimal points:
```
2.6
+ 5.7
------
8.3
```
-
Result: \( 8.3 \)
---
5. \( 74.8 + 10.57 \)
- Align the decimal points:
```
74.80
+ 10.57
--------
85.37
```
-
Result: \( 85.37 \)
---
6. \( 36.831 - 29.266 \)
- Align the decimal points:
```
36.831
- 29.266
---------
7.565
```
-
Result: \( 7.565 \)
---
7. \( 1.49 + 4.78 \)
- Align the decimal points:
```
1.49
+ 4.78
------
6.27
```
-
Result: \( 6.27 \)
---
8. \( 93.10 - 12.401 \)
- Align the decimal points:
```
93.100
- 12.401
---------
80.699
```
-
Result: \( 80.699 \)
---
9. \( 41.933 - 27.958 \)
- Align the decimal points:
```
41.933
- 27.958
---------
13.975
```
-
Result: \( 13.975 \)
---
10. \( 1.57 + 2.65 \)
- Align the decimal points:
```
1.57
+ 2.65
------
4.22
```
-
Result: \( 4.22 \)
---
11. \( 68.61 - 45.752 \)
- Align the decimal points:
```
68.610
- 45.752
---------
22.858
```
-
Result: \( 22.858 \)
---
12. \( 80.915 - 78.398 \)
- Align the decimal points:
```
80.915
- 78.398
---------
2.517
```
-
Result: \( 2.517 \)
---
Final Answers:
\[
\boxed{
\begin{array}{ccc}
9.2 & 65.48 & 20.991 \\
8.3 & 85.37 & 7.565 \\
6.27 & 80.699 & 13.975 \\
4.22 & 22.858 & 2.517 \\
\end{array}
}
\]
Parent Tip: Review the logic above to help your child master the concept of adding and subtracting decimals worksheet 4th grade.