B=52, and the maximum remainder is less than the divisor.

Three digits m = 53a+52 = 53 (a+1)-1.

That is, three digits are multiples of 53-1.

1000÷53≈ 18.9

18x53=954 is the largest three digits.

That is a+ 1= 18.

a= 17

The maximum value of a+b = 17+52=69.

Law of division:

Operational properties of division

1, the dividend is enlarged (reduced) by n times, and the quotient is correspondingly enlarged (reduced) by n times under the condition that the divisor is unchanged.

2. The divisor is expanded (reduced) by n times, while the dividend is unchanged, and the quotient is correspondingly reduced (expanded) by n times.

3. Dividing the dividend by two divisors is equal to dividing by the product of these two divisors.

Partial correlation formula:

1, dividend = quotient

2. Dividend = divisor

3, divisor × quotient = dividend

4. Divider = (dividend-remainder) quotient

5, quotient = (dividend-remainder) ÷ divisor