We look at the division of 3307690 by 21 
Our goal is to divide 3307690 by 21.

On to step 1:
The number 21 fits into 3 0 times, leaving a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Grab the next digit (3) from the dividend, add it to 3, then carry on: 33 / 21

Moving on to step 2:
21 goes into 33 1 times with a remainder of 12.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 21 from 33 and we're left with 12.
Fetch the next digit (0) from the dividend, attach it to 12 and continue: 120 / 21

Advancing to step 3:
21 can be fit into 120 5 times, resulting in a remainder of 15.
The next digit of our result is 5. 
Result so far: 15.0
Deduct 105 from 120 and we're left with 15.
Bring next digit (7) of the dividend behind the 15 and repeat the process: 157 / 21

Advancing to step 4:
21 can be fit into 157 7 times, resulting in a remainder of 10.
Use 7 as the next digit of our solution. 
Result so far: 157.0
Subtracting 147 from 157 leaves us with 10.
Bring next digit (6) of the dividend behind the 10 and repeat the process: 106 / 21

Step 5:
The number 21 fits into 106 5 times, leaving a remainder of 1.
Record the quotient 5 as the next digit in the result. 
Result so far: 1575.0
Subtracting 105 from 106 leaves us with 1.
Take the next digit (9) from the dividend and append it to 1, then repeat: 19 / 21

Going ahead to step 6:
If we divide 19 by 21, we get 0 and a remainder of 19.
Record the quotient 0 as the next digit in the result. 
Result so far: 15750.0
If we take 0 away from 19, we end up with 19.
Take the next digit (0) from the dividend and append it to 19, then repeat: 190 / 21

Let's proceed to step 7:
21 goes into 190 9 times with a remainder of 1.
The next digit of our result is 9. 
Result so far: 157509.0
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 8:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The next digit of our result is 0. 
Result so far: 157509.0
Subtract 0 from 10 to 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:
100 divided by 21 is 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 157509.04
Subtract 84 from 100 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 10:
21 goes into 160 7 times with a remainder of 13.
The next digit of our result is 7. 
Result so far: 157509.047
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

On to step 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 157509.0476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 12:
21 can be fit into 40 1 times, resulting in a remainder of 19.
The next digit of our result is 1. 
Result so far: 157509.04761
Deduct 21 from 40 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 13:
21 goes into 190 9 times with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 157509.047619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 14:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 157509.047619
Subtract 0 from 10 to 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.

Going ahead to step 15:
If we divide 100 by 21, we get 4 and a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 157509.04761904
Deduct 84 from 100 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

After the division, we end up with 157509.04761904 and a remainder of 1.6e-08.