1. Move the decimal point:

Start with the original number: 0.0000638

Move the decimal point 5 places to the right: 6.38

2. Count the decimal places moved:

You moved the decimal point 5 places to the right.

3. Express the result:

The number you obtained is 6.38.

Since you moved the decimal right, the exponent is negative: -5.

Therefore, 0.0000638 in scientific notation is 6.38 x 10⁻⁵