We look at the division of 87237 by 53 
The aim is to understand the frequency of 53 in 87237.

On to step 1:
The number 53 fits into 8 0 times, leaving a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 53

Going ahead to step 2:
If we divide 87 by 53, we get 1 and a remainder of 34.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 34 after subtracting 53 from 87.
Append the next digit (2) from the dividend to 34 and continue with: 342 / 53

Step 3:
53 goes into 342 6 times with a remainder of 24.
Use 6 as the next digit of our solution. 
Result so far: 16.0
Subtract 318 from 342 to get 24.
Include the next digit (3) from the dividend after 24, then repeat: 243 / 53

On to step 4:
53 can be fit into 243 4 times, resulting in a remainder of 31.
Put 4 as the next digit of the answer. 
Result so far: 164.0
Deduct 212 from 243 and we're left with 31.
Take the next digit (7) from the dividend and append it to 31, then repeat: 317 / 53

Let's proceed to step 5:
When dividing 317 by 53, we get 5 with a remainder of 52.
Put 5 as the next digit of the answer. 
Result so far: 1645.0
Deduct 265 from 317 and we're left with 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Moving on to step 6:
53 can be fit into 520 9 times, resulting in a remainder of 43.
Record the quotient 9 as the next digit in the result. 
Result so far: 1645.9
Subtract 477 from 520 to get 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Going ahead to step 7:
When dividing 430 by 53, we get 8 with a remainder of 6.
Record the quotient 8 as the next digit in the result. 
Result so far: 1645.98
Deduct 424 from 430 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 8:
60 divided by 53 is 1 with a remainder of 7.
Use 1 as the next digit of our solution. 
Result so far: 1645.981
Subtract 53 from 60 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 9:
When dividing 70 by 53, we get 1 with a remainder of 17.
The number 1 becomes the next digit in our result. 
Result so far: 1645.9811
The remainder is 17 after subtracting 53 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

The final result is 1645.9811 with a remainder of 0.00017.