91696638 ÷ 640 
The aim is to understand the frequency of 640 in 91696638.

Moving on to step 1:
640 can be fit into 9 0 times, resulting in a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Fetch the next digit (1) from the dividend, attach it to 9 and continue: 91 / 640

Let's proceed to step 2:
If we divide 91 by 640, we get 0 and a remainder of 91.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 91 to get 91.
Bring next digit (6) of the dividend behind the 91 and repeat the process: 916 / 640

Step 3:
640 can be fit into 916 1 times, resulting in a remainder of 276.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 640 from 916, we get 276.
Take the next digit (9) from the dividend and append it to 276, then repeat: 2769 / 640

Let's proceed to step 4:
640 goes into 2769 4 times with a remainder of 209.
The next digit of our result is 4. 
Result so far: 14.0
The remainder is 209 after subtracting 2560 from 2769.
Include the next digit (6) from the dividend after 209, then repeat: 2096 / 640

Going ahead to step 5:
2096 divided by 640 is 3 with a remainder of 176.
Write down 3 as next digit of the result. 
Result so far: 143.0
Deduct 1920 from 2096 and we're left with 176.
Take the next digit (6) from the dividend and append it to 176, then repeat: 1766 / 640

Advancing to step 6:
640 goes into 1766 2 times with a remainder of 486.
Write down 2 as next digit of the result. 
Result so far: 1432.0
Deduct 1280 from 1766 and we're left with 486.
Grab the next digit (3) from the dividend, add it to 486, then carry on: 4863 / 640

On to step 7:
If we divide 4863 by 640, we get 7 and a remainder of 383.
Record the quotient 7 as the next digit in the result. 
Result so far: 14327.0
If we take 4480 away from 4863, we end up with 383.
Fetch the next digit (8) from the dividend, attach it to 383 and continue: 3838 / 640

Step 8:
If we divide 3838 by 640, we get 5 and a remainder of 638.
Write down 5 as next digit of the result. 
Result so far: 143275.0
Subtract 3200 from 3838 to get 638.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6380, and continue the process.

Advancing to step 9:
When dividing 6380 by 640, we get 9 with a remainder of 620.
Put 9 as the next digit of the answer. 
Result so far: 143275.9
Deduct 5760 from 6380 and we're left with 620.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6200, and continue the process.

Step 10:
6200 divided by 640 is 9 with a remainder of 440.
The number 9 becomes the next digit in our result. 
Result so far: 143275.99
The remainder is 440 after subtracting 5760 from 6200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4400, and continue the process.

The final result is 143275.99 with a remainder of 0.44.