Let's divide 81129 by 40
We want to divide 81129 by 40.

On to step 1:
8 divided by 40 is 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (1) from the dividend, add it to 8, then carry on: 81 / 40

Moving on to step 2:
The number 40 fits into 81 2 times, leaving a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtracting 80 from 81 leaves us with 1.
Take the next digit (1) from the dividend and append it to 1, then repeat: 11 / 40

Going ahead to step 3:
40 can be fit into 11 0 times, resulting in a remainder of 11.
Record the quotient 0 as the next digit in the result. 
Result so far: 20.0
The remainder is 11 after subtracting 0 from 11.
Bring next digit (2) of the dividend behind the 11 and repeat the process: 112 / 40

Advancing to step 4:
If we divide 112 by 40, we get 2 and a remainder of 32.
Record the quotient 2 as the next digit in the result. 
Result so far: 202.0
Subtract 80 from 112 to get 32.
Bring next digit (9) of the dividend behind the 32 and repeat the process: 329 / 40

Going ahead to step 5:
40 goes into 329 8 times with a remainder of 9.
Put 8 as the next digit of the answer. 
Result so far: 2028.0
If we subtract 320 from 329, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 6:
The number 40 fits into 90 2 times, leaving a remainder of 10.
Put 2 as the next digit of the answer. 
Result so far: 2028.2
Subtracting 80 from 90 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
40 can be fit into 100 2 times, resulting in a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 2028.22
If we subtract 80 from 100, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final result is 2028.22 with a remainder of 0.02.