We look at the division of 20151155 by 720 
The aim is to understand the frequency of 720 in 20151155.

On to step 1:
If we divide 2 by 720, we get 0 and a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 720

Let's proceed to step 2:
When dividing 20 by 720, we get 0 with a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 20 leaves us with 20.
Take the next digit (1) from the dividend and append it to 20, then repeat: 201 / 720

Moving on to step 3:
If we divide 201 by 720, we get 0 and a remainder of 201.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 201, we get 201.
Append the next digit (5) from the dividend to 201 and continue with: 2015 / 720

Moving on to step 4:
720 goes into 2015 2 times with a remainder of 575.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Deduct 1440 from 2015 and we're left with 575.
Include the next digit (1) from the dividend after 575, then repeat: 5751 / 720

Moving on to step 5:
When dividing 5751 by 720, we get 7 with a remainder of 711.
The number 7 becomes the next digit in our result. 
Result so far: 27.0
If we take 5040 away from 5751, we end up with 711.
Take the next digit (1) from the dividend and append it to 711, then repeat: 7111 / 720

Going ahead to step 6:
720 goes into 7111 9 times with a remainder of 631.
Record the quotient 9 as the next digit in the result. 
Result so far: 279.0
Subtract 6480 from 7111 to get 631.
Fetch the next digit (5) from the dividend, attach it to 631 and continue: 6315 / 720

Moving on to step 7:
The number 720 fits into 6315 8 times, leaving a remainder of 555.
Put 8 as the next digit of the answer. 
Result so far: 2798.0
If we subtract 5760 from 6315, we get 555.
Append the next digit (5) from the dividend to 555 and continue with: 5555 / 720

On to step 8:
720 can be fit into 5555 7 times, resulting in a remainder of 515.
Put 7 as the next digit of the answer. 
Result so far: 27987.0
If we subtract 5040 from 5555, we get 515.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5150, and continue the process.

On to step 9:
If we divide 5150 by 720, we get 7 and a remainder of 110.
The number 7 becomes the next digit in our result. 
Result so far: 27987.7
Deduct 5040 from 5150 and we're left with 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1100, and continue the process.

Let's proceed to step 10:
When dividing 1100 by 720, we get 1 with a remainder of 380.
Record the quotient 1 as the next digit in the result. 
Result so far: 27987.71
If we take 720 away from 1100, we end up with 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

Moving on to step 11:
3800 divided by 720 is 5 with a remainder of 200.
Put 5 as the next digit of the answer. 
Result so far: 27987.715
Deduct 3600 from 3800 and we're left with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Going ahead to step 12:
If we divide 2000 by 720, we get 2 and a remainder of 560.
The next digit of our result is 2. 
Result so far: 27987.7152
If we subtract 1440 from 2000, we get 560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5600, and continue the process.

On to step 13:
If we divide 5600 by 720, we get 7 and a remainder of 560.
Write down 7 as next digit of the result. 
Result so far: 27987.71527
If we take 5040 away from 5600, we end up with 560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5600, and continue the process.

Moving on to step 14:
720 can be fit into 5600 7 times, resulting in a remainder of 560.
Write down 7 as next digit of the result. 
Result so far: 27987.715277
If we subtract 5040 from 5600, we get 560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5600, and continue the process.

Our division results in 27987.715277 with a remaining 5.6e-05.