We look at the division of 21558987 by 316 
The aim is to understand the frequency of 316 in 21558987.

Step 1:
316 can be fit into 2 0 times, resulting in a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 316

Let's proceed to step 2:
If we divide 21 by 316, we get 0 and a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Include the next digit (5) from the dividend after 21, then repeat: 215 / 316

Step 3:
215 divided by 316 is 0 with a remainder of 215.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 215, we get 215.
Append the next digit (5) from the dividend to 215 and continue with: 2155 / 316

Advancing to step 4:
When dividing 2155 by 316, we get 6 with a remainder of 259.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we subtract 1896 from 2155, we get 259.
Grab the next digit (8) from the dividend, add it to 259, then carry on: 2598 / 316

Step 5:
316 goes into 2598 8 times with a remainder of 70.
Record the quotient 8 as the next digit in the result. 
Result so far: 68.0
If we subtract 2528 from 2598, we get 70.
Take the next digit (9) from the dividend and append it to 70, then repeat: 709 / 316

Advancing to step 6:
If we divide 709 by 316, we get 2 and a remainder of 77.
The next digit of our result is 2. 
Result so far: 682.0
The remainder is 77 after subtracting 632 from 709.
Take the next digit (8) from the dividend and append it to 77, then repeat: 778 / 316

Moving on to step 7:
If we divide 778 by 316, we get 2 and a remainder of 146.
Record the quotient 2 as the next digit in the result. 
Result so far: 6822.0
Subtract 632 from 778 to get 146.
Bring next digit (7) of the dividend behind the 146 and repeat the process: 1467 / 316

Going ahead to step 8:
If we divide 1467 by 316, we get 4 and a remainder of 203.
Use 4 as the next digit of our solution. 
Result so far: 68224.0
The remainder is 203 after subtracting 1264 from 1467.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2030, and continue the process.

Moving on to step 9:
If we divide 2030 by 316, we get 6 and a remainder of 134.
The next digit of our result is 6. 
Result so far: 68224.6
Subtracting 1896 from 2030 leaves us with 134.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1340, and continue the process.

Step 10:
The number 316 fits into 1340 4 times, leaving a remainder of 76.
Put 4 as the next digit of the answer. 
Result so far: 68224.64
Deduct 1264 from 1340 and we're left with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Going ahead to step 11:
If we divide 760 by 316, we get 2 and a remainder of 128.
The next digit of our result is 2. 
Result so far: 68224.642
Subtract 632 from 760 to get 128.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1280, and continue the process.

Step 12:
If we divide 1280 by 316, we get 4 and a remainder of 16.
The next digit of our result is 4. 
Result so far: 68224.6424
Deduct 1264 from 1280 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.

Step 13:
If we divide 160 by 316, we get 0 and a remainder of 160.
Write down 0 as next digit of the result. 
Result so far: 68224.6424
Deduct 0 from 160 and we're left with 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Advancing to step 14:
When dividing 1600 by 316, we get 5 with a remainder of 20.
Use 5 as the next digit of our solution. 
Result so far: 68224.642405
If we subtract 1580 from 1600, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 15:
When dividing 200 by 316, we get 0 with a remainder of 200.
The number 0 becomes the next digit in our result. 
Result so far: 68224.642405
Subtract 0 from 200 to get 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Step 16:
If we divide 2000 by 316, we get 6 and a remainder of 104.
Write down 6 as next digit of the result. 
Result so far: 68224.64240506
Subtract 1896 from 2000 to get 104.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1040, and continue the process.

After the division, we end up with 68224.64240506 and a remainder of 1.04e-07.