Let's divide 21158515 by 681
The aim is to understand the frequency of 681 in 21158515.

Moving on to step 1:
When dividing 2 by 681, we get 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 681

Going ahead to step 2:
681 can be fit into 21 0 times, resulting in a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 21, we end up with 21.
Fetch the next digit (1) from the dividend, attach it to 21 and continue: 211 / 681

Step 3:
211 divided by 681 is 0 with a remainder of 211.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 211 after subtracting 0 from 211.
Take the next digit (5) from the dividend and append it to 211, then repeat: 2115 / 681

Let's proceed to step 4:
2115 divided by 681 is 3 with a remainder of 72.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we subtract 2043 from 2115, we get 72.
Bring next digit (8) of the dividend behind the 72 and repeat the process: 728 / 681

Step 5:
The number 681 fits into 728 1 times, leaving a remainder of 47.
The next digit of our result is 1. 
Result so far: 31.0
Subtract 681 from 728 to get 47.
Append the next digit (5) from the dividend to 47 and continue with: 475 / 681

On to step 6:
681 can be fit into 475 0 times, resulting in a remainder of 475.
Write down 0 as next digit of the result. 
Result so far: 310.0
If we subtract 0 from 475, we get 475.
Append the next digit (1) from the dividend to 475 and continue with: 4751 / 681

Moving on to step 7:
When dividing 4751 by 681, we get 6 with a remainder of 665.
The next digit of our result is 6. 
Result so far: 3106.0
Deduct 4086 from 4751 and we're left with 665.
Fetch the next digit (5) from the dividend, attach it to 665 and continue: 6655 / 681

Step 8:
6655 divided by 681 is 9 with a remainder of 526.
The number 9 becomes the next digit in our result. 
Result so far: 31069.0
Deduct 6129 from 6655 and we're left with 526.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5260, and continue the process.

Advancing to step 9:
681 goes into 5260 7 times with a remainder of 493.
Use 7 as the next digit of our solution. 
Result so far: 31069.7
If we subtract 4767 from 5260, we get 493.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4930, and continue the process.

Let's proceed to step 10:
When dividing 4930 by 681, we get 7 with a remainder of 163.
The number 7 becomes the next digit in our result. 
Result so far: 31069.77
The remainder is 163 after subtracting 4767 from 4930.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1630, and continue the process.

The final outcome is 31069.77, with a leftover of 0.163.