Let's divide 21299 by 86
We're looking to find how many times 86 goes into 21299.

Advancing to step 1:
86 can be fit into 2 0 times, resulting in a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 86

On to step 2:
If we divide 21 by 86, we get 0 and a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Bring next digit (2) of the dividend behind the 21 and repeat the process: 212 / 86

Let's proceed to step 3:
If we divide 212 by 86, we get 2 and a remainder of 40.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we take 172 away from 212, we end up with 40.
Append the next digit (9) from the dividend to 40 and continue with: 409 / 86

Going ahead to step 4:
If we divide 409 by 86, we get 4 and a remainder of 65.
Record the quotient 4 as the next digit in the result. 
Result so far: 24.0
If we subtract 344 from 409, we get 65.
Take the next digit (9) from the dividend and append it to 65, then repeat: 659 / 86

Advancing to step 5:
If we divide 659 by 86, we get 7 and a remainder of 57.
Put 7 as the next digit of the answer. 
Result so far: 247.0
If we take 602 away from 659, we end up with 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Going ahead to step 6:
86 goes into 570 6 times with a remainder of 54.
Use 6 as the next digit of our solution. 
Result so far: 247.6
Subtracting 516 from 570 leaves us with 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Step 7:
86 goes into 540 6 times with a remainder of 24.
Record the quotient 6 as the next digit in the result. 
Result so far: 247.66
Deduct 516 from 540 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

After the division, we end up with 247.66 and a remainder of 0.024.