We look at the division of 369567 by 21 
We want to figure out the number of times 369567 can be divided by 21.

Let's proceed to step 1:
If we divide 3 by 21, we get 0 and a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Grab the next digit (6) from the dividend, add it to 3, then carry on: 36 / 21

Step 2:
21 can be fit into 36 1 times, resulting in a remainder of 15.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 21 from 36 leaves us with 15.
Bring next digit (9) of the dividend behind the 15 and repeat the process: 159 / 21

Let's proceed to step 3:
If we divide 159 by 21, we get 7 and a remainder of 12.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
If we subtract 147 from 159, we get 12.
Bring next digit (5) of the dividend behind the 12 and repeat the process: 125 / 21

Moving on to step 4:
21 goes into 125 5 times with a remainder of 20.
Use 5 as the next digit of our solution. 
Result so far: 175.0
If we take 105 away from 125, we end up with 20.
Take the next digit (6) from the dividend and append it to 20, then repeat: 206 / 21

Step 5:
If we divide 206 by 21, we get 9 and a remainder of 17.
Use 9 as the next digit of our solution. 
Result so far: 1759.0
Subtract 189 from 206 to get 17.
Take the next digit (7) from the dividend and append it to 17, then repeat: 177 / 21

Going ahead to step 6:
177 divided by 21 is 8 with a remainder of 9.
The number 8 becomes the next digit in our result. 
Result so far: 17598.0
If we take 168 away from 177, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 7:
90 divided by 21 is 4 with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 17598.4
Deduct 84 from 90 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 17598.42
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 9:
180 divided by 21 is 8 with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 17598.428
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 10:
If we divide 120 by 21, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 17598.4285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 11:
21 goes into 150 7 times with a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 17598.42857
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 12:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 17598.428571
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 13:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 17598.4285714
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 14:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 17598.42857142
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

The final result is 17598.42857142 with a remainder of 1.8e-08.