Look at the top of the first horizontal line first.

Subtract two squares from the first three squares of dividend.

The difference is 1 digit.

And 1, 2, 3, MINUS 4, 5, there is a loan.

Explain the tens of thousands of digits of dividends. ① The location can only be 1.

After borrowing 1, ② the position is at least 10, and the difference is 0 after subtracting ④ the position.

Then the number of position ④ is 9 and the number of position ② is 0.

And ③-⑤ and loans.

Pet-name ruby position is 9.

6. The location is 1.

The last two digits of the divisor, 28, drop directly.

⑦ The position of quotient is 0.

Then multiply the last bit of the quotient by the last bit of the divisor to judge that the last bit of the product is 8.

There are several combinations of 1×8, 2×4, 2× 9, 3× 6, 4× 7 and 6× 8.

Attending position is 2, and attending position is 9, which is easy to test.

There is a picture, which may be slow, and so on.