2) 53 1/7=75 ..6

1): The hundred digits are 3, the quotient is 3, and the hundred digits are gone, so the divisor can only be 9. The second step, the unit is 3, only 7*9=63, so the quotient is 37, the dividend is 9, and the rest is easy to calculate.

2) The idea is still based on a hundred. The quotient is 7, and the second step is gone, so the divisor can only be 7 or 8. The other bit is 1, the remainder is 6, so it won't be 8, the multiple of 8 is even, and the remainder is even, so the dividend is 7; According to the remainder of the second step is 6, and the quotient of the second step is 5, so the quotient is 75 and the dividend is 7.