Adding Decimals Using Grids Worksheets - Free Printable

Let's solve each of the decimal addition problems using the grid method. The goal is to align the decimal points and add the numbers column by column, carrying over when necessary.

We’ll go through each problem one by one:

---

1)

```
40.6
+163.8
-------
```

Step-by-step:

- Align decimals:
```
40.6
+163.8
------
```

- Add the tenths place: 6 + 8 = 14 → write down 4, carry over 1
- Add the units place: 0 + 3 = 3, plus carry-over 1 = 4
- Add tens place: 4 + 6 = 10 → write 0, carry over 1
- Add hundreds place: 0 + 1 = 1, plus carry-over 1 = 2

So:
```
40.6
+163.8
------
204.4
```

✔ Answer: 204.4

---

2)

```
112.9
+ 670.3
-------
```

- Tenths: 9 + 3 = 12 → write 2, carry 1
- Units: 2 + 0 = 2, plus carry 1 = 3
- Tens: 1 + 7 = 8
- Hundreds: 1 + 6 = 7

```
112.9
+ 670.3
-------
783.2
```

✔ Answer: 783.2

---

3)

```
204.4
+ 378.1
-------
```

- Tenths: 4 + 1 = 5
- Units: 4 + 8 = 12 → write 2, carry 1
- Tens: 0 + 7 = 7, plus carry 1 = 8
- Hundreds: 2 + 3 = 5

```
204.4
+ 378.1
-------
582.5
```

✔ Answer: 582.5

---

4)

```
7.2
+ 709.5
-------
```

Align decimals:
```
7.2
+709.5
------
```

- Tenths: 2 + 5 = 7
- Units: 7 + 9 = 16 → write 6, carry 1
- Tens: 0 + 0 = 0, plus carry 1 = 1
- Hundreds: 0 + 7 = 7

```
7.2
+ 709.5
-------
716.7
```

✔ Answer: 716.7

---

5)

```
0.7
+ 85.2
-------
```

```
0.7
+ 85.2
------
```

- Tenths: 7 + 2 = 9
- Units: 0 + 5 = 5
- Tens: 0 + 8 = 8

```
0.7
+ 85.2
------
85.9
```

✔ Answer: 85.9

---

6)

```
69.1
+ 23.8
-------
```

- Tenths: 1 + 8 = 9
- Units: 9 + 3 = 12 → write 2, carry 1
- Tens: 6 + 2 = 8, plus carry 1 = 9

```
69.1
+ 23.8
------
92.9
```

✔ Answer: 92.9

---

7)

```
943.5
+ 60.9
-------
```

- Tenths: 5 + 9 = 14 → write 4, carry 1
- Units: 3 + 0 = 3, plus carry 1 = 4
- Tens: 4 + 6 = 10 → write 0, carry 1
- Hundreds: 9 + 0 = 9, plus carry 1 = 10

```
943.5
+ 60.9
-------
1004.4
```

✔ Answer: 1004.4

---

8)

```
452.6
+ 1.3
-------
```

- Tenths: 6 + 3 = 9
- Units: 2 + 1 = 3
- Tens: 5 + 0 = 5
- Hundreds: 4 + 0 = 4

```
452.6
+ 1.3
-------
453.9
```

✔ Answer: 453.9

---

9)

```
5.3
+ 2.6
-------
```

- Tenths: 3 + 6 = 9
- Units: 5 + 2 = 7

```
5.3
+ 2.6
-------
7.9
```

✔ Answer: 7.9

---

10)

```
37.8
+ 496.2
-------
```

- Tenths: 8 + 2 = 10 → write 0, carry 1
- Units: 7 + 6 = 13, plus carry 1 = 14 → write 4, carry 1
- Tens: 3 + 9 = 12, plus carry 1 = 13 → write 3, carry 1
- Hundreds: 0 + 4 = 4, plus carry 1 = 5

```
37.8
+496.2
------
534.0
```

✔ Answer: 534.0 (or just 534)

---

✔ Final Answers:

| Problem | Answer |
|--------|------------|
| 1) | 204.4 |
| 2) | 783.2 |
| 3) | 582.5 |
| 4) | 716.7 |
| 5) | 85.9 |
| 6) | 92.9 |
| 7) | 1004.4 |
| 8) | 453.9 |
| 9) | 7.9 |
| 10) | 534.0 (or 534) |

---

📝 Explanation:

- Always align decimal points.
- Add digits from right to left, starting with tenths.
- Carry over when the sum in a column exceeds 9.
- Place the decimal point directly below the others.

Let me know if you'd like this formatted as a filled-in grid!