What is the smallest number that must be added to 3,875 so that the result is exactly divisible by 9?

💡 Solution & Explanation

Divide 3,875 by 9: the quotient is 430 and the remainder is 5. To reach the next multiple of 9, add 9 − 5 = 4. Check: 3,875 + 4 = 3,879, which is 9 × 431. Note that 5 is the number to subtract, not add, to get a multiple of 9.