Adding and Subtracting Decimals Worksheets - Math Monks - Free Printable

Here are the solutions to all 16 problems on the worksheet, with step-by-step explanations for each. All calculations are done by aligning decimal points and adding or subtracting digit by digit, carrying or borrowing as needed — just like whole number arithmetic, but with attention to place value.

---

① 3.897 + 1.127 =

```
3.897
+ 1.127
-------
5.024
```

- Thousandths: 7 + 7 = 14 → write 4, carry 1
- Hundredths: 9 + 2 + 1 = 12 → write 2, carry 1
- Tenths: 8 + 1 + 1 = 10 → write 0, carry 1
- Units: 3 + 1 + 1 = 5

✔ Answer: 5.024

---

② 9.387 - 1.819 =

```
9.387
- 1.819
-------
7.568
```

- Thousandths: 7 - 9 → borrow → 17 - 9 = 8
- Hundredths: 8 becomes 7; 7 - 1 = 6
- Tenths: 3 - 8 → borrow → 13 - 8 = 5
- Units: 9 becomes 8; 8 - 1 = 7

✔ Answer: 7.568

---

③ 1.944 - 1.174 =

```
1.944
- 1.174
-------
0.770
```

- Thousandths: 4 - 4 = 0
- Hundredths: 4 - 7 → borrow → 14 - 7 = 7
- Tenths: 9 becomes 8; 8 - 1 = 7
- Units: 1 - 1 = 0

✔ Answer: 0.770 (can also be written as 0.77)

---

④ 5.234 + 4.199 =

```
5.234
+ 4.199
-------
9.433
```

- Thousandths: 4 + 9 = 13 → write 3, carry 1
- Hundredths: 3 + 9 + 1 = 13 → write 3, carry 1
- Tenths: 2 + 1 + 1 = 4
- Units: 5 + 4 = 9

✔ Answer: 9.433

---

⑤ 3.092 - 1.308 =

```
3.092
- 1.308
-------
1.784
```

- Thousandths: 2 - 8 → borrow → 12 - 8 = 4
- Hundredths: 9 becomes 8; 8 - 0 = 8
- Tenths: 0 - 3 → borrow → 10 - 3 = 7
- Units: 3 becomes 2; 2 - 1 = 1

✔ Answer: 1.784

---

⑥ 4.448 - 3.432 =

```
4.448
- 3.432
-------
1.016
```

- Thousandths: 8 - 2 = 6
- Hundredths: 4 - 3 = 1
- Tenths: 4 - 4 = 0
- Units: 4 - 3 = 1

✔ Answer: 1.016

---

⑦ 9.423 + 3.231 =

```
9.423
+ 3.231
-------
12.654
```

- Thousandths: 3 + 1 = 4
- Hundredths: 2 + 3 = 5
- Tenths: 4 + 2 = 6
- Units: 9 + 3 = 12 → write 2, carry 1 to tens → 1 in tens place

✔ Answer: 12.654

---

⑧ 4.982 - 2.999 =

```
4.982
- 2.999
-------
1.983
```

- Thousandths: 2 - 9 → borrow → 12 - 9 = 3
- Hundredths: 8 becomes 7; 7 - 9 → borrow → 17 - 9 = 8
- Tenths: 9 becomes 8; 8 - 9 → borrow → 18 - 9 = 9
- Units: 4 becomes 3; 3 - 2 = 1

✔ Answer: 1.983

---

⑨ 7.224 + 6.331 =

```
7.224
+ 6.331
-------
13.555
```

- Thousandths: 4 + 1 = 5
- Hundredths: 2 + 3 = 5
- Tenths: 2 + 3 = 5
- Units: 7 + 6 = 13 → write 3, carry 1 → 1 in tens

✔ Answer: 13.555

---

⑩ 6.104 - 5.503 =

```
6.104
- 5.503
-------
0.601
```

- Thousandths: 4 - 3 = 1
- Hundredths: 0 - 0 = 0
- Tenths: 1 - 5 → borrow → 11 - 5 = 6
- Units: 6 becomes 5; 5 - 5 = 0

✔ Answer: 0.601

---

⑪ 5.204 + 5.199 =

```
5.204
+ 5.199
-------
10.403
```

- Thousandths: 4 + 9 = 13 → write 3, carry 1
- Hundredths: 0 + 9 + 1 = 10 → write 0, carry 1
- Tenths: 2 + 1 + 1 = 4
- Units: 5 + 5 = 10 → write 0, carry 1 → 1 in tens

✔ Answer: 10.403

---

⑫ 6.290 + 8.980 =

```
6.290
+ 8.980
-------
15.270
```

- Thousandths: 0 + 0 = 0
- Hundredths: 9 + 8 = 17 → write 7, carry 1
- Tenths: 2 + 9 + 1 = 12 → write 2, carry 1
- Units: 6 + 8 + 1 = 15 → write 5, carry 1 → 1 in tens

✔ Answer: 15.270 (or 15.27)

---

⑬ 0.987 + 3.442 =

```
0.987
+ 3.442
-------
4.429
```

- Thousandths: 7 + 2 = 9
- Hundredths: 8 + 4 = 12 → write 2, carry 1
- Tenths: 9 + 4 + 1 = 14 → write 4, carry 1
- Units: 0 + 3 + 1 = 4

✔ Answer: 4.429

---

⑭ 7.434 + 6.177 =

```
7.434
+ 6.177
-------
13.611
```

- Thousandths: 4 + 7 = 11 → write 1, carry 1
- Hundredths: 3 + 7 + 1 = 11 → write 1, carry 1
- Tenths: 4 + 1 + 1 = 6
- Units: 7 + 6 = 13 → write 3, carry 1 → 1 in tens

✔ Answer: 13.611

---

⑮ 3.997 - 2.813 =

```
3.997
- 2.813
-------
1.184
```

- Thousandths: 7 - 3 = 4
- Hundredths: 9 - 1 = 8
- Tenths: 9 - 8 = 1
- Units: 3 - 2 = 1

✔ Answer: 1.184

---

⑯ 3.143 - 0.198 =

```
3.143
- 0.198
-------
2.945
```

- Thousandths: 3 - 8 → borrow → 13 - 8 = 5
- Hundredths: 4 becomes 3; 3 - 9 → borrow → 13 - 9 = 4
- Tenths: 1 becomes 0; 0 - 1 → borrow → 10 - 1 = 9
- Units: 3 becomes 2; 2 - 0 = 2

✔ Answer: 2.945

---

## ✔ Final Answers:

① 5.024
② 7.568
③ 0.770
④ 9.433
⑤ 1.784
⑥ 1.016
⑦ 12.654
⑧ 1.983
⑨ 13.555
⑩ 0.601
⑪ 10.403
⑫ 15.270
⑬ 4.429
⑭ 13.611
⑮ 1.184
⑯ 2.945

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