We're dividing 63990072 by 421 
Let's see how many times 421 fits into 63990072.

On to step 1:
421 goes into 6 0 times with a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 421

Moving on to step 2:
If we divide 63 by 421, we get 0 and a remainder of 63.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 63 to get 63.
Bring next digit (9) of the dividend behind the 63 and repeat the process: 639 / 421

Step 3:
421 can be fit into 639 1 times, resulting in a remainder of 218.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 421 from 639 leaves us with 218.
Append the next digit (9) from the dividend to 218 and continue with: 2189 / 421

Step 4:
If we divide 2189 by 421, we get 5 and a remainder of 84.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
If we take 2105 away from 2189, we end up with 84.
Bring next digit (0) of the dividend behind the 84 and repeat the process: 840 / 421

Let's proceed to step 5:
421 goes into 840 1 times with a remainder of 419.
Use 1 as the next digit of our solution. 
Result so far: 151.0
Deduct 421 from 840 and we're left with 419.
Grab the next digit (0) from the dividend, add it to 419, then carry on: 4190 / 421

Advancing to step 6:
4190 divided by 421 is 9 with a remainder of 401.
Write down 9 as next digit of the result. 
Result so far: 1519.0
Deduct 3789 from 4190 and we're left with 401.
Take the next digit (7) from the dividend and append it to 401, then repeat: 4017 / 421

On to step 7:
When dividing 4017 by 421, we get 9 with a remainder of 228.
Write down 9 as next digit of the result. 
Result so far: 15199.0
Subtracting 3789 from 4017 leaves us with 228.
Take the next digit (2) from the dividend and append it to 228, then repeat: 2282 / 421

Moving on to step 8:
2282 divided by 421 is 5 with a remainder of 177.
The number 5 becomes the next digit in our result. 
Result so far: 151995.0
The remainder is 177 after subtracting 2105 from 2282.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1770, and continue the process.

Advancing to step 9:
If we divide 1770 by 421, we get 4 and a remainder of 86.
Record the quotient 4 as the next digit in the result. 
Result so far: 151995.4
Deduct 1684 from 1770 and we're left with 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Going ahead to step 10:
421 goes into 860 2 times with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 151995.42
Subtract 842 from 860 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 11:
If we divide 180 by 421, we get 0 and a remainder of 180.
Use 0 as the next digit of our solution. 
Result so far: 151995.42
The remainder is 180 after subtracting 0 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Let's proceed to step 12:
421 goes into 1800 4 times with a remainder of 116.
The number 4 becomes the next digit in our result. 
Result so far: 151995.4204
If we take 1684 away from 1800, we end up with 116.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1160, and continue the process.

On to step 13:
When dividing 1160 by 421, we get 2 with a remainder of 318.
Write down 2 as next digit of the result. 
Result so far: 151995.42042
If we take 842 away from 1160, we end up with 318.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3180, and continue the process.

Let's proceed to step 14:
The number 421 fits into 3180 7 times, leaving a remainder of 233.
Write down 7 as next digit of the result. 
Result so far: 151995.420427
Subtract 2947 from 3180 to get 233.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2330, and continue the process.

Step 15:
When dividing 2330 by 421, we get 5 with a remainder of 225.
Put 5 as the next digit of the answer. 
Result so far: 151995.4204275
The remainder is 225 after subtracting 2105 from 2330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2250, and continue the process.

Let's proceed to step 16:
421 can be fit into 2250 5 times, resulting in a remainder of 145.
Write down 5 as next digit of the result. 
Result so far: 151995.42042755
If we subtract 2105 from 2250, we get 145.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1450, and continue the process.

The final result is 151995.42042755 with a remainder of 1.45e-07.