Dividend Divider = 7...6

Dividend+Dividend =83- 13=70

The sum of the two is 70, and there is a remainder of 6, which means that as long as the dividend is subtracted from 6, there is no remainder and it is divisible. Then use 70-6

70-6 is actually the sum of dividend and divisor, but if it is a new dividend, should the quotient be divided by another divisor, so to get the original divisor, one must be added to the quotient.

That is, (70-6)÷(7+ 1)=8.