How many 4 digit numbers that are multiples of 9?

Well, honey, to find the number of 4-digit multiples of 9, you just need to divide the largest 4-digit multiple of 9 (9999) by 9 and subtract the smallest 4-digit multiple of 9 (1008) divided by 9. So, 9999 ÷ 9 - 1008 ÷ 9 = 1111 - 112 = 999. That's right, there are 999 4-digit numbers that are multiples of 9.