We look at the division of 87638 by 87 
The aim is to understand the frequency of 87 in 87638.

Let's proceed to step 1:
87 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Append the next digit (7) from the dividend to 8 and continue with: 87 / 87

Step 2:
The number 87 fits into 87 1 times, leaving a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 87 from 87 and we're left with 0.
Grab the next digit (6) from the dividend, add it to 0, then carry on: 6 / 87

Moving on to step 3:
87 goes into 6 0 times with a remainder of 6.
The next digit of our result is 0. 
Result so far: 10.0
Subtracting 0 from 6 leaves us with 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 87

Let's proceed to step 4:
87 can be fit into 63 0 times, resulting in a remainder of 63.
Record the quotient 0 as the next digit in the result. 
Result so far: 100.0
Deduct 0 from 63 and we're left with 63.
Append the next digit (8) from the dividend to 63 and continue with: 638 / 87

Advancing to step 5:
The number 87 fits into 638 7 times, leaving a remainder of 29.
Put 7 as the next digit of the answer. 
Result so far: 1007.0
Subtract 609 from 638 to get 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Moving on to step 6:
When dividing 290 by 87, we get 3 with a remainder of 29.
The next digit of our result is 3. 
Result so far: 1007.3
If we take 261 away from 290, we end up with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Let's proceed to step 7:
87 can be fit into 290 3 times, resulting in a remainder of 29.
The next digit of our result is 3. 
Result so far: 1007.33
The remainder is 29 after subtracting 261 from 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

After the division, we end up with 1007.33 and a remainder of 0.029.