15423189 ÷ 421 
We're looking to find how many times 421 goes into 15423189.

Step 1:
421 can be fit into 1 0 times, resulting in a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Include the next digit (5) from the dividend after 1, then repeat: 15 / 421

Advancing to step 2:
15 divided by 421 is 0 with a remainder of 15.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 15 after subtracting 0 from 15.
Bring next digit (4) of the dividend behind the 15 and repeat the process: 154 / 421

Advancing to step 3:
If we divide 154 by 421, we get 0 and a remainder of 154.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 154 and we're left with 154.
Append the next digit (2) from the dividend to 154 and continue with: 1542 / 421

Let's proceed to step 4:
421 goes into 1542 3 times with a remainder of 279.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtract 1263 from 1542 to get 279.
Fetch the next digit (3) from the dividend, attach it to 279 and continue: 2793 / 421

On to step 5:
When dividing 2793 by 421, we get 6 with a remainder of 267.
Write down 6 as next digit of the result. 
Result so far: 36.0
Subtract 2526 from 2793 to get 267.
Bring next digit (1) of the dividend behind the 267 and repeat the process: 2671 / 421

Let's proceed to step 6:
2671 divided by 421 is 6 with a remainder of 145.
Put 6 as the next digit of the answer. 
Result so far: 366.0
Deduct 2526 from 2671 and we're left with 145.
Grab the next digit (8) from the dividend, add it to 145, then carry on: 1458 / 421

On to step 7:
The number 421 fits into 1458 3 times, leaving a remainder of 195.
The number 3 becomes the next digit in our result. 
Result so far: 3663.0
Subtracting 1263 from 1458 leaves us with 195.
Grab the next digit (9) from the dividend, add it to 195, then carry on: 1959 / 421

On to step 8:
If we divide 1959 by 421, we get 4 and a remainder of 275.
The number 4 becomes the next digit in our result. 
Result so far: 36634.0
Subtract 1684 from 1959 to get 275.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2750, and continue the process.

Going ahead to step 9:
421 goes into 2750 6 times with a remainder of 224.
The number 6 becomes the next digit in our result. 
Result so far: 36634.6
If we take 2526 away from 2750, we end up with 224.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2240, and continue the process.

Let's proceed to step 10:
When dividing 2240 by 421, we get 5 with a remainder of 135.
Put 5 as the next digit of the answer. 
Result so far: 36634.65
Deduct 2105 from 2240 and we're left with 135.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1350, and continue the process.

Going ahead to step 11:
1350 divided by 421 is 3 with a remainder of 87.
The number 3 becomes the next digit in our result. 
Result so far: 36634.653
Subtracting 1263 from 1350 leaves us with 87.
Since there are no more digits in the dividend, we add a zero to the remainder making it 870, and continue the process.

Moving on to step 12:
421 goes into 870 2 times with a remainder of 28.
Record the quotient 2 as the next digit in the result. 
Result so far: 36634.6532
Deduct 842 from 870 and we're left with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 13:
When dividing 280 by 421, we get 0 with a remainder of 280.
Record the quotient 0 as the next digit in the result. 
Result so far: 36634.6532
Deduct 0 from 280 and we're left with 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Step 14:
421 goes into 2800 6 times with a remainder of 274.
Write down 6 as next digit of the result. 
Result so far: 36634.653206
The remainder is 274 after subtracting 2526 from 2800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2740, and continue the process.

Moving on to step 15:
The number 421 fits into 2740 6 times, leaving a remainder of 214.
Use 6 as the next digit of our solution. 
Result so far: 36634.6532066
The remainder is 214 after subtracting 2526 from 2740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2140, and continue the process.

Our division results in 36634.6532066 with a remaining 2.14e-06.