This document discusses the relationship between division and subtraction through examples and exercises. It shows that the quotient in a division number sentence represents the number of times the divisor can be subtracted from the dividend to get zero. For example, 20 ÷ 4 = 5 because 5 is the number of times 4 can be subtracted from 20 (20 - 4 - 4 - 4 - 4 - 4 = 0). The document guides students through building subtraction expressions that correspond to division sentences and proves this is true for any numbers.