21237559 ÷ 649 
The aim is to understand the frequency of 649 in 21237559.

Let's proceed to step 1:
649 goes into 2 0 times with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 649

On to step 2:
649 can be fit into 21 0 times, resulting in a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Grab the next digit (2) from the dividend, add it to 21, then carry on: 212 / 649

Step 3:
649 goes into 212 0 times with a remainder of 212.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 212 and we're left with 212.
Append the next digit (3) from the dividend to 212 and continue with: 2123 / 649

On to step 4:
If we divide 2123 by 649, we get 3 and a remainder of 176.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 1947 from 2123, we get 176.
Include the next digit (7) from the dividend after 176, then repeat: 1767 / 649

Advancing to step 5:
649 goes into 1767 2 times with a remainder of 469.
Use 2 as the next digit of our solution. 
Result so far: 32.0
Subtracting 1298 from 1767 leaves us with 469.
Grab the next digit (5) from the dividend, add it to 469, then carry on: 4695 / 649

Going ahead to step 6:
The number 649 fits into 4695 7 times, leaving a remainder of 152.
Write down 7 as next digit of the result. 
Result so far: 327.0
If we subtract 4543 from 4695, we get 152.
Include the next digit (5) from the dividend after 152, then repeat: 1525 / 649

On to step 7:
The number 649 fits into 1525 2 times, leaving a remainder of 227.
The next digit of our result is 2. 
Result so far: 3272.0
Subtract 1298 from 1525 to get 227.
Take the next digit (9) from the dividend and append it to 227, then repeat: 2279 / 649

On to step 8:
If we divide 2279 by 649, we get 3 and a remainder of 332.
Use 3 as the next digit of our solution. 
Result so far: 32723.0
The remainder is 332 after subtracting 1947 from 2279.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3320, and continue the process.

Moving on to step 9:
3320 divided by 649 is 5 with a remainder of 75.
Record the quotient 5 as the next digit in the result. 
Result so far: 32723.5
If we subtract 3245 from 3320, we get 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Going ahead to step 10:
649 goes into 750 1 times with a remainder of 101.
Put 1 as the next digit of the answer. 
Result so far: 32723.51
If we subtract 649 from 750, we get 101.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1010, and continue the process.

On to step 11:
If we divide 1010 by 649, we get 1 and a remainder of 361.
Write down 1 as next digit of the result. 
Result so far: 32723.511
Deduct 649 from 1010 and we're left with 361.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3610, and continue the process.

Our division results in 32723.511 with a remaining 0.0361.