Add :
9.999,0.03

Answer

To solve the problem of adding the decimals 9.999 and 0.03, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Numbers**: We have two decimal numbers:
- First number: 9.999
- Second number: 0.03

2. **Convert to Like Decimals**:
- The first number (9.999) has 3 decimal places.
- The second number (0.03) has 2 decimal places.
- To make them like decimals, we need to add one more decimal place to the second number. We can do this by adding a zero at the end:
- 0.03 becomes 0.030.

3. **Align the Numbers**:
- Write the numbers one under the other, aligning the decimal points:
```
9.999
+ 0.030
```

4. **Add the Numbers**:
- Start adding from the rightmost side (the thousandths place):
- Thousandths: 9 + 0 = 9
- Hundredths: 9 + 3 = 12 (write down 2 and carry over 1)
- Tenths: 9 + 0 + 1 (carried over) = 10 (write down 0 and carry over 1)
- Units: 9 + 0 + 1 (carried over) = 10 (write down 0 and carry over 1)
- Finally, we have the carried over 1 in the thousands place.

5. **Write the Final Answer**:
- The final result after adding is 10.029.

### Final Answer:
10.029