The distance between two numbers on the number line can be found by taking the absolute difference between them. Given the numbers -9.9 and 6.2, you can find the distance as follows:
1. **Subtract the two numbers**:
\[6.2 - (-9.9).\]
2. **Simplify**:
When subtracting a negative number, you can add the positive equivalent:
\[6.2 + 9.9 = 16.1.\]
Thus, the distance between -9.9 and 6.2 is **16.1** units.