703804 ÷ 21 
The aim is to understand the frequency of 21 in 703804.

Step 1:
When dividing 7 by 21, we get 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Include the next digit (0) from the dividend after 7, then repeat: 70 / 21

Advancing to step 2:
21 goes into 70 3 times with a remainder of 7.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtract 63 from 70 to get 7.
Append the next digit (3) from the dividend to 7 and continue with: 73 / 21

Moving on to step 3:
When dividing 73 by 21, we get 3 with a remainder of 10.
The next digit of our result is 3. 
Result so far: 33.0
Subtract 63 from 73 to get 10.
Take the next digit (8) from the dividend and append it to 10, then repeat: 108 / 21

On to step 4:
The number 21 fits into 108 5 times, leaving a remainder of 3.
Use 5 as the next digit of our solution. 
Result so far: 335.0
Subtracting 105 from 108 leaves us with 3.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 21

Let's proceed to step 5:
21 goes into 30 1 times with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 3351.0
If we take 21 away from 30, we end up with 9.
Fetch the next digit (4) from the dividend, attach it to 9 and continue: 94 / 21

Advancing to step 6:
If we divide 94 by 21, we get 4 and a remainder of 10.
Put 4 as the next digit of the answer. 
Result so far: 33514.0
Subtracting 84 from 94 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 7:
21 goes into 100 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 33514.4
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.

Step 8:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 33514.47
If we take 147 away from 160, we end up 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 9:
If we divide 130 by 21, we get 6 and a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 33514.476
If we subtract 126 from 130, we 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 10:
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: 33514.4761
Subtract 21 from 40 to get 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 11:
If we divide 190 by 21, we get 9 and a remainder of 1.
The next digit of our result is 9. 
Result so far: 33514.47619
Subtracting 189 from 190 leaves us 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.

Advancing to step 12:
The number 21 fits into 10 0 times, leaving a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 33514.47619
If we subtract 0 from 10, we 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 13:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 33514.4761904
If we take 84 away from 100, we end up 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.

Moving on to step 14:
21 goes into 160 7 times with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 33514.47619047
If we take 147 away from 160, we end up 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.

The quotient of the division is 33514.47619047, and the remainder is 1.3e-08.