We're dividing 21175976 by 561 
The aim is to understand the frequency of 561 in 21175976.

Moving on to step 1:
When dividing 2 by 561, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 561

Going ahead to step 2:
If we divide 21 by 561, we get 0 and a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Append the next digit (1) from the dividend to 21 and continue with: 211 / 561

Advancing to step 3:
561 goes into 211 0 times with a remainder of 211.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 211 and we're left with 211.
Grab the next digit (7) from the dividend, add it to 211, then carry on: 2117 / 561

Going ahead to step 4:
When dividing 2117 by 561, we get 3 with a remainder of 434.
Write down 3 as next digit of the result. 
Result so far: 3.0
Deduct 1683 from 2117 and we're left with 434.
Include the next digit (5) from the dividend after 434, then repeat: 4345 / 561

Moving on to step 5:
When dividing 4345 by 561, we get 7 with a remainder of 418.
Write down 7 as next digit of the result. 
Result so far: 37.0
Subtract 3927 from 4345 to get 418.
Append the next digit (9) from the dividend to 418 and continue with: 4189 / 561

Going ahead to step 6:
If we divide 4189 by 561, we get 7 and a remainder of 262.
Use 7 as the next digit of our solution. 
Result so far: 377.0
Subtract 3927 from 4189 to get 262.
Append the next digit (7) from the dividend to 262 and continue with: 2627 / 561

Let's proceed to step 7:
561 can be fit into 2627 4 times, resulting in a remainder of 383.
The next digit of our result is 4. 
Result so far: 3774.0
The remainder is 383 after subtracting 2244 from 2627.
Grab the next digit (6) from the dividend, add it to 383, then carry on: 3836 / 561

Advancing to step 8:
When dividing 3836 by 561, we get 6 with a remainder of 470.
The next digit of our result is 6. 
Result so far: 37746.0
If we subtract 3366 from 3836, we get 470.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4700, and continue the process.

Moving on to step 9:
When dividing 4700 by 561, we get 8 with a remainder of 212.
Record the quotient 8 as the next digit in the result. 
Result so far: 37746.8
If we take 4488 away from 4700, we end up with 212.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2120, and continue the process.

On to step 10:
561 can be fit into 2120 3 times, resulting in a remainder of 437.
The number 3 becomes the next digit in our result. 
Result so far: 37746.83
If we take 1683 away from 2120, we end up with 437.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4370, and continue the process.

Going ahead to step 11:
4370 divided by 561 is 7 with a remainder of 443.
The number 7 becomes the next digit in our result. 
Result so far: 37746.837
Subtract 3927 from 4370 to get 443.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4430, and continue the process.

Advancing to step 12:
561 can be fit into 4430 7 times, resulting in a remainder of 503.
The next digit of our result is 7. 
Result so far: 37746.8377
Subtracting 3927 from 4430 leaves us with 503.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5030, and continue the process.

After the division, we end up with 37746.8377 and a remainder of 0.00503.