1. The problem asks: If the decimal moves one place to the left, which operation does that represent and why? 2. When you multiply a number by 10, the decimal point moves one place to the right, making the number 10 times larger. 3. When you divide a number by 10, the decimal point moves one place to the left, making the number 10 times smaller. 4. Addition or subtraction do not affect the position of the decimal point in this way; they change the value by adding or subtracting. 5. Therefore, moving the decimal one place to the left corresponds to division by 10. 6. Next, explain how dividing by 100 affects the decimal point. 7. Dividing by 100 is dividing by $10^2$, so the decimal moves two places to the left. 8. This means the digit shifts two places left, making the number 100 times smaller. 9. The correct answers are: - Moving decimal one place left: Division by 10. - Dividing by 100 moves decimal two places left. Final answers: - Moving decimal one place left represents division by 10. - Dividing by 100 moves decimal two places to the left.