274484 divided by 21 
The aim is to understand the frequency of 21 in 274484.

On to step 1:
21 goes into 2 0 times with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Fetch the next digit (7) from the dividend, attach it to 2 and continue: 27 / 21

Advancing to step 2:
27 divided by 21 is 1 with a remainder of 6.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 21 from 27 leaves us with 6.
Include the next digit (4) from the dividend after 6, then repeat: 64 / 21

Step 3:
21 goes into 64 3 times with a remainder of 1.
The next digit of our result is 3. 
Result so far: 13.0
If we take 63 away from 64, we end up with 1.
Fetch the next digit (4) from the dividend, attach it to 1 and continue: 14 / 21

Advancing to step 4:
The number 21 fits into 14 0 times, leaving a remainder of 14.
The next digit of our result is 0. 
Result so far: 130.0
The remainder is 14 after subtracting 0 from 14.
Append the next digit (8) from the dividend to 14 and continue with: 148 / 21

Advancing to step 5:
If we divide 148 by 21, we get 7 and a remainder of 1.
Record the quotient 7 as the next digit in the result. 
Result so far: 1307.0
Subtracting 147 from 148 leaves us with 1.
Include the next digit (4) from the dividend after 1, then repeat: 14 / 21

On to step 6:
14 divided by 21 is 0 with a remainder of 14.
Use 0 as the next digit of our solution. 
Result so far: 13070.0
The remainder is 14 after subtracting 0 from 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 7:
21 can be fit into 140 6 times, resulting in a remainder of 14.
The number 6 becomes the next digit in our result. 
Result so far: 13070.6
Subtract 126 from 140 to get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Step 8:
If we divide 140 by 21, we get 6 and a remainder of 14.
The number 6 becomes the next digit in our result. 
Result so far: 13070.66
Subtracting 126 from 140 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Our division results in 13070.66 with a remaining 0.014.