We're dividing 21512171 by 136 
The aim is to understand the frequency of 136 in 21512171.

Step 1:
When dividing 2 by 136, we get 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 136

Step 2:
When dividing 21 by 136, we get 0 with a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Fetch the next digit (5) from the dividend, attach it to 21 and continue: 215 / 136

Moving on to step 3:
When dividing 215 by 136, we get 1 with a remainder of 79.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we take 136 away from 215, we end up with 79.
Append the next digit (1) from the dividend to 79 and continue with: 791 / 136

Advancing to step 4:
When dividing 791 by 136, we get 5 with a remainder of 111.
Write down 5 as next digit of the result. 
Result so far: 15.0
Deduct 680 from 791 and we're left with 111.
Grab the next digit (2) from the dividend, add it to 111, then carry on: 1112 / 136

Step 5:
If we divide 1112 by 136, we get 8 and a remainder of 24.
Write down 8 as next digit of the result. 
Result so far: 158.0
Deduct 1088 from 1112 and we're left with 24.
Append the next digit (1) from the dividend to 24 and continue with: 241 / 136

Moving on to step 6:
When dividing 241 by 136, we get 1 with a remainder of 105.
Record the quotient 1 as the next digit in the result. 
Result so far: 1581.0
Deduct 136 from 241 and we're left with 105.
Append the next digit (7) from the dividend to 105 and continue with: 1057 / 136

Advancing to step 7:
136 goes into 1057 7 times with a remainder of 105.
Use 7 as the next digit of our solution. 
Result so far: 15817.0
Subtract 952 from 1057 to get 105.
Take the next digit (1) from the dividend and append it to 105, then repeat: 1051 / 136

Let's proceed to step 8:
136 goes into 1051 7 times with a remainder of 99.
Record the quotient 7 as the next digit in the result. 
Result so far: 158177.0
If we take 952 away from 1051, we end up with 99.
Since there are no more digits in the dividend, we add a zero to the remainder making it 990, and continue the process.

Step 9:
136 can be fit into 990 7 times, resulting in a remainder of 38.
Record the quotient 7 as the next digit in the result. 
Result so far: 158177.7
Deduct 952 from 990 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Step 10:
If we divide 380 by 136, we get 2 and a remainder of 108.
Write down 2 as next digit of the result. 
Result so far: 158177.72
Deduct 272 from 380 and we're left with 108.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Let's proceed to step 11:
1080 divided by 136 is 7 with a remainder of 128.
Use 7 as the next digit of our solution. 
Result so far: 158177.727
Subtracting 952 from 1080 leaves us with 128.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1280, and continue the process.

Let's proceed to step 12:
1280 divided by 136 is 9 with a remainder of 56.
The next digit of our result is 9. 
Result so far: 158177.7279
Subtracting 1224 from 1280 leaves us with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Step 13:
When dividing 560 by 136, we get 4 with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 158177.72794
If we take 544 away from 560, 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.

Advancing to step 14:
136 goes into 160 1 times with a remainder of 24.
Put 1 as the next digit of the answer. 
Result so far: 158177.727941
Subtract 136 from 160 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 15:
The number 136 fits into 240 1 times, leaving a remainder of 104.
Record the quotient 1 as the next digit in the result. 
Result so far: 158177.7279411
If we subtract 136 from 240, we 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.

The final outcome is 158177.7279411, with a leftover of 1.04e-06.