please help me fast with explanation

Answer:
1. Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10. The sign of the exponent will depend on the direction you are moving the decimal. 4.8×10−23
2. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
3.888×10^10
3.The sign of the exponent will depend on the direction you are moving the decimal.4.2×10−3
Just use the same explanation in number 1 to get the right answer.