277510 ÷ 21 
The aim is to understand the frequency of 21 in 277510.

Advancing to step 1:
When dividing 2 by 21, we get 0 with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Fetch the next digit (7) from the dividend, attach it to 2 and continue: 27 / 21

Moving on to step 2:
The number 21 fits into 27 1 times, leaving a remainder of 6.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtracting 21 from 27 leaves us with 6.
Take the next digit (7) from the dividend and append it to 6, then repeat: 67 / 21

Moving on to step 3:
If we divide 67 by 21, we get 3 and a remainder of 4.
The next digit of our result is 3. 
Result so far: 13.0
Deduct 63 from 67 and we're left with 4.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 21

Advancing to step 4:
The number 21 fits into 45 2 times, leaving a remainder of 3.
Write down 2 as next digit of the result. 
Result so far: 132.0
Subtract 42 from 45 to get 3.
Include the next digit (1) from the dividend after 3, then repeat: 31 / 21

Going ahead to step 5:
31 divided by 21 is 1 with a remainder of 10.
Record the quotient 1 as the next digit in the result. 
Result so far: 1321.0
If we subtract 21 from 31, we get 10.
Take the next digit (0) from the dividend and append it to 10, then repeat: 100 / 21

Advancing to step 6:
If we divide 100 by 21, we get 4 and a remainder of 16.
The next digit of our result is 4. 
Result so far: 13214.0
The remainder is 16 after subtracting 84 from 100.
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 7:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 13214.7
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.

Let's proceed to step 8:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 13214.76
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.

Advancing to step 9:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 13214.761
Subtracting 21 from 40 leaves us 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.

Step 10:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 13214.7619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
When dividing 10 by 21, we get 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 13214.7619
Subtracting 0 from 10 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 12:
The number 21 fits into 100 4 times, leaving a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 13214.761904
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.

Going ahead to step 13:
If we divide 160 by 21, we get 7 and a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 13214.7619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 14:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 13214.76190476
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final result is 13214.76190476 with a remainder of 4e-09.