Because in a division formula, the relationship between dividend, remainder, divisor and quotient is: (dividend-remainder) ÷ divisor = quotient, which is recorded as: dividend ÷ divisor = quotient ÷ remainder, and then the quotient × divisor+remainder = dividend is derived.
Knowledge expansion: complete quotient
When the number A is divided by the number B (non-zero), its quotient is called complete quotient. For example, 9÷3=3, and 3 is the complete quotient.
Incomplete quotient
If the number A is divided by the number B (non-zero), the quotient obtained is incomplete. For example: 10 ÷ 3 = 3... 1, where 3 is an incomplete quotient.