We're dividing 51516120 by 155 
The aim is to understand the frequency of 155 in 51516120.

Moving on to step 1:
When dividing 5 by 155, we get 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Take the next digit (1) from the dividend and append it to 5, then repeat: 51 / 155

On to step 2:
155 can be fit into 51 0 times, resulting in a remainder of 51.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 51, we get 51.
Bring next digit (5) of the dividend behind the 51 and repeat the process: 515 / 155

Going ahead to step 3:
155 can be fit into 515 3 times, resulting in a remainder of 50.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtracting 465 from 515 leaves us with 50.
Bring next digit (1) of the dividend behind the 50 and repeat the process: 501 / 155

Advancing to step 4:
155 can be fit into 501 3 times, resulting in a remainder of 36.
Put 3 as the next digit of the answer. 
Result so far: 33.0
If we subtract 465 from 501, we get 36.
Fetch the next digit (6) from the dividend, attach it to 36 and continue: 366 / 155

Let's proceed to step 5:
When dividing 366 by 155, we get 2 with a remainder of 56.
Record the quotient 2 as the next digit in the result. 
Result so far: 332.0
Subtracting 310 from 366 leaves us with 56.
Fetch the next digit (1) from the dividend, attach it to 56 and continue: 561 / 155

Step 6:
When dividing 561 by 155, we get 3 with a remainder of 96.
Record the quotient 3 as the next digit in the result. 
Result so far: 3323.0
Subtract 465 from 561 to get 96.
Grab the next digit (2) from the dividend, add it to 96, then carry on: 962 / 155

Going ahead to step 7:
155 can be fit into 962 6 times, resulting in a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 33236.0
Subtract 930 from 962 to get 32.
Bring next digit (0) of the dividend behind the 32 and repeat the process: 320 / 155

Step 8:
If we divide 320 by 155, we get 2 and a remainder of 10.
Put 2 as the next digit of the answer. 
Result so far: 332362.0
Subtracting 310 from 320 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.

Step 9:
155 goes into 100 0 times with a remainder of 100.
The next digit of our result is 0. 
Result so far: 332362.0
Deduct 0 from 100 and we're left with 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Advancing to step 10:
155 goes into 1000 6 times with a remainder of 70.
Write down 6 as next digit of the result. 
Result so far: 332362.06
Subtract 930 from 1000 to get 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

On to step 11:
155 goes into 700 4 times with a remainder of 80.
Record the quotient 4 as the next digit in the result. 
Result so far: 332362.064
Subtract 620 from 700 to get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Going ahead to step 12:
155 can be fit into 800 5 times, resulting in a remainder of 25.
Record the quotient 5 as the next digit in the result. 
Result so far: 332362.0645
Deduct 775 from 800 and we're left with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Step 13:
If we divide 250 by 155, we get 1 and a remainder of 95.
Write down 1 as next digit of the result. 
Result so far: 332362.06451
Subtract 155 from 250 to get 95.
Since there are no more digits in the dividend, we add a zero to the remainder making it 950, and continue the process.

Moving on to step 14:
155 can be fit into 950 6 times, resulting in a remainder of 20.
The number 6 becomes the next digit in our result. 
Result so far: 332362.064516
Deduct 930 from 950 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 15:
155 can be fit into 200 1 times, resulting in a remainder of 45.
Write down 1 as next digit of the result. 
Result so far: 332362.0645161
Subtracting 155 from 200 leaves us with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

On to step 16:
450 divided by 155 is 2 with a remainder of 140.
Write down 2 as next digit of the result. 
Result so far: 332362.06451612
If we subtract 310 from 450, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

After the division, we end up with 332362.06451612 and a remainder of 1.4e-07.