We divide 215122 by 42
We want to figure out the number of times 215122 can be divided by 42.

Going ahead to step 1:
The number 42 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 42

On to step 2:
If we divide 21 by 42, we get 0 and a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Append the next digit (5) from the dividend to 21 and continue with: 215 / 42

Let's proceed to step 3:
215 divided by 42 is 5 with a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 5.0
Subtract 210 from 215 to get 5.
Fetch the next digit (1) from the dividend, attach it to 5 and continue: 51 / 42

Step 4:
42 goes into 51 1 times with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 51.0
Subtract 42 from 51 to get 9.
Append the next digit (2) from the dividend to 9 and continue with: 92 / 42

On to step 5:
The number 42 fits into 92 2 times, leaving a remainder of 8.
The next digit of our result is 2. 
Result so far: 512.0
Subtract 84 from 92 to get 8.
Append the next digit (2) from the dividend to 8 and continue with: 82 / 42

Step 6:
42 goes into 82 1 times with a remainder of 40.
The number 1 becomes the next digit in our result. 
Result so far: 5121.0
Subtract 42 from 82 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.

Going ahead to step 7:
The number 42 fits into 400 9 times, leaving a remainder of 22.
Write down 9 as next digit of the result. 
Result so far: 5121.9
Deduct 378 from 400 and we're left with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Moving on to step 8:
42 can be fit into 220 5 times, resulting in a remainder of 10.
Record the quotient 5 as the next digit in the result. 
Result so far: 5121.95
If we subtract 210 from 220, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 9:
If we divide 100 by 42, we get 2 and a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 5121.952
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 10:
42 can be fit into 160 3 times, resulting in a remainder of 34.
Use 3 as the next digit of our solution. 
Result so far: 5121.9523
If we take 126 away from 160, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Going ahead to step 11:
42 goes into 340 8 times with a remainder of 4.
The next digit of our result is 8. 
Result so far: 5121.95238
Subtracting 336 from 340 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 12:
If we divide 40 by 42, we get 0 and a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 5121.95238
Subtract 0 from 40 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.

On to step 13:
42 can be fit into 400 9 times, resulting in a remainder of 22.
Put 9 as the next digit of the answer. 
Result so far: 5121.9523809
The remainder is 22 after subtracting 378 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Let's proceed to step 14:
42 goes into 220 5 times with a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 5121.95238095
If we take 210 away from 220, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

After the division, we end up with 5121.95238095 and a remainder of 1e-08.