Here's how to get it:

1. Move the decimal point one place to the right: This gives us 1.3.

2. Count the number of places you moved the decimal: We moved it one place to the right.

3. Since we moved the decimal to the right, the exponent is negative: So, the exponent is -1.

Therefore, 0.13 in scientific notation is 1.3 x 10^-1.