Answer :

To add the numbers 0.34, 2.3, 5.4, and 0.67, aligning the decimal points helps keep the columns of digits properly arranged for manual addition. Here's a step-by-step explanation of how you can add these numbers properly.

1. Write each number ensuring that the decimal points are aligned vertically:
```
0.34
2.30
5.40
0.67
```

2. Add each column starting from the rightmost digit.
- Start with the hundredths column (the second decimal place):
```
4 (from 0.34)
+ 0 (from 2.30)
+ 0 (from 5.40)
+ 7 (from 0.67)
--------
11
```

- Write down 1 and carry over 1 to the tenths column (the first decimal place).

3. Move to the tenths column:
```
3 (from 0.34)
+ 3 (from 2.30)
+ 4 (from 5.40)
+ 6 (from 0.67)
+ 1 (carried over)
------
17
```

- Write down 7 and carry over 1 to the units column.

4. Now add the units column (to the left of the decimal point):
```
0 (from 0.34)
+ 2 (from 2.30)
+ 5 (from 5.40)
+ 0 (from 0.67)
+ 1 (carried over)
------
8
```

5. Write down the 8. Since there's no need to carry over any value, we complete the addition.

Putting it all together, we get:
```
7.0
+1.7
------
8.71
```

Therefore, the sum of 0.34, 2.3, 5.4, and 0.67 is 8.71.

So the correct answer is:
O True