Let's divide 309721 by 90
We want to figure out the number of times 309721 can be divided by 90.

Let's proceed to step 1:
The number 90 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 90

On to step 2:
90 can be fit into 30 0 times, resulting in a remainder of 30.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 30 leaves us with 30.
Fetch the next digit (9) from the dividend, attach it to 30 and continue: 309 / 90

On to step 3:
90 can be fit into 309 3 times, resulting in a remainder of 39.
Write down 3 as next digit of the result. 
Result so far: 3.0
Subtracting 270 from 309 leaves us with 39.
Fetch the next digit (7) from the dividend, attach it to 39 and continue: 397 / 90

Going ahead to step 4:
90 goes into 397 4 times with a remainder of 37.
The number 4 becomes the next digit in our result. 
Result so far: 34.0
The remainder is 37 after subtracting 360 from 397.
Append the next digit (2) from the dividend to 37 and continue with: 372 / 90

Going ahead to step 5:
90 goes into 372 4 times with a remainder of 12.
Put 4 as the next digit of the answer. 
Result so far: 344.0
If we subtract 360 from 372, we get 12.
Take the next digit (1) from the dividend and append it to 12, then repeat: 121 / 90

On to step 6:
90 goes into 121 1 times with a remainder of 31.
Write down 1 as next digit of the result. 
Result so far: 3441.0
Subtracting 90 from 121 leaves us with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Advancing to step 7:
When dividing 310 by 90, we get 3 with a remainder of 40.
Record the quotient 3 as the next digit in the result. 
Result so far: 3441.3
Subtracting 270 from 310 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 8:
400 divided by 90 is 4 with a remainder of 40.
Record the quotient 4 as the next digit in the result. 
Result so far: 3441.34
The remainder is 40 after subtracting 360 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Advancing to step 9:
90 goes into 400 4 times with a remainder of 40.
The next digit of our result is 4. 
Result so far: 3441.344
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Our division results in 3441.344 with a remaining 0.004.