We're dividing 15880424 by 421 
We want to divide 15880424 by 421.

Let's proceed to step 1:
If we divide 1 by 421, we get 0 and a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 421

On to step 2:
If we divide 15 by 421, we get 0 and a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 15 to get 15.
Grab the next digit (8) from the dividend, add it to 15, then carry on: 158 / 421

Advancing to step 3:
If we divide 158 by 421, we get 0 and a remainder of 158.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 158 after subtracting 0 from 158.
Fetch the next digit (8) from the dividend, attach it to 158 and continue: 1588 / 421

Advancing to step 4:
If we divide 1588 by 421, we get 3 and a remainder of 325.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 1263 from 1588 leaves us with 325.
Bring next digit (0) of the dividend behind the 325 and repeat the process: 3250 / 421

Going ahead to step 5:
If we divide 3250 by 421, we get 7 and a remainder of 303.
Use 7 as the next digit of our solution. 
Result so far: 37.0
Subtract 2947 from 3250 to get 303.
Grab the next digit (4) from the dividend, add it to 303, then carry on: 3034 / 421

Advancing to step 6:
The number 421 fits into 3034 7 times, leaving a remainder of 87.
Put 7 as the next digit of the answer. 
Result so far: 377.0
Subtracting 2947 from 3034 leaves us with 87.
Include the next digit (2) from the dividend after 87, then repeat: 872 / 421

Advancing to step 7:
When dividing 872 by 421, we get 2 with a remainder of 30.
Use 2 as the next digit of our solution. 
Result so far: 3772.0
Deduct 842 from 872 and we're left with 30.
Append the next digit (4) from the dividend to 30 and continue with: 304 / 421

Going ahead to step 8:
421 can be fit into 304 0 times, resulting in a remainder of 304.
Record the quotient 0 as the next digit in the result. 
Result so far: 37720.0
If we subtract 0 from 304, we get 304.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3040, and continue the process.

Advancing to step 9:
The number 421 fits into 3040 7 times, leaving a remainder of 93.
The number 7 becomes the next digit in our result. 
Result so far: 37720.7
Subtracting 2947 from 3040 leaves us with 93.
Since there are no more digits in the dividend, we add a zero to the remainder making it 930, and continue the process.

Let's proceed to step 10:
If we divide 930 by 421, we get 2 and a remainder of 88.
Record the quotient 2 as the next digit in the result. 
Result so far: 37720.72
Deduct 842 from 930 and we're left with 88.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

Step 11:
421 goes into 880 2 times with a remainder of 38.
Record the quotient 2 as the next digit in the result. 
Result so far: 37720.722
Subtract 842 from 880 to get 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

The final outcome is 37720.722, with a leftover of 0.0038.