We divide 281392 by 21
The aim is to understand the frequency of 21 in 281392.

Advancing to step 1:
If we divide 2 by 21, we get 0 and 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.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 21

Let's proceed to step 2:
If we divide 28 by 21, we get 1 and a remainder of 7.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 21 away from 28, we end up with 7.
Append the next digit (1) from the dividend to 7 and continue with: 71 / 21

Moving on to step 3:
The number 21 fits into 71 3 times, leaving a remainder of 8.
Put 3 as the next digit of the answer. 
Result so far: 13.0
If we take 63 away from 71, we end up with 8.
Append the next digit (3) from the dividend to 8 and continue with: 83 / 21

Moving on to step 4:
83 divided by 21 is 3 with a remainder of 20.
Put 3 as the next digit of the answer. 
Result so far: 133.0
Subtract 63 from 83 to get 20.
Append the next digit (9) from the dividend to 20 and continue with: 209 / 21

Let's proceed to step 5:
209 divided by 21 is 9 with a remainder of 20.
The number 9 becomes the next digit in our result. 
Result so far: 1339.0
The remainder is 20 after subtracting 189 from 209.
Bring next digit (2) of the dividend behind the 20 and repeat the process: 202 / 21

On to step 6:
21 goes into 202 9 times with a remainder of 13.
Put 9 as the next digit of the answer. 
Result so far: 13399.0
If we take 189 away from 202, 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.

Going ahead to step 7:
130 divided by 21 is 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 13399.6
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.

Going ahead to step 8:
If we divide 40 by 21, we get 1 and a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 13399.61
If we subtract 21 from 40, we 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.

Moving on to step 9:
21 goes into 190 9 times with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 13399.619
Subtract 189 from 190 to get 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 10:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 13399.619
Subtract 0 from 10 to 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.

Moving on to step 11:
If we divide 100 by 21, we get 4 and a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 13399.61904
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.

On to step 12:
If we divide 160 by 21, we get 7 and a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 13399.619047
Deduct 147 from 160 and we're left 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.

On to step 13:
When dividing 130 by 21, we get 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 13399.6190476
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 14:
If we divide 40 by 21, we get 1 and a remainder of 19.
The next digit of our result is 1. 
Result so far: 13399.61904761
Deduct 21 from 40 and we're left 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.

The quotient of the division is 13399.61904761, and the remainder is 1.9e-08.