687360 ÷ 90 
The aim is to understand the frequency of 90 in 687360.

Let's proceed to step 1:
The number 90 fits into 6 0 times, leaving a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Append the next digit (8) from the dividend to 6 and continue with: 68 / 90

Step 2:
90 can be fit into 68 0 times, resulting in a remainder of 68.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 68 to get 68.
Fetch the next digit (7) from the dividend, attach it to 68 and continue: 687 / 90

Moving on to step 3:
If we divide 687 by 90, we get 7 and a remainder of 57.
The next digit of our result is 7. 
Result so far: 7.0
Deduct 630 from 687 and we're left with 57.
Grab the next digit (3) from the dividend, add it to 57, then carry on: 573 / 90

Going ahead to step 4:
90 goes into 573 6 times with a remainder of 33.
Use 6 as the next digit of our solution. 
Result so far: 76.0
Subtracting 540 from 573 leaves us with 33.
Take the next digit (6) from the dividend and append it to 33, then repeat: 336 / 90

Let's proceed to step 5:
The number 90 fits into 336 3 times, leaving a remainder of 66.
Use 3 as the next digit of our solution. 
Result so far: 763.0
If we take 270 away from 336, we end up with 66.
Fetch the next digit (0) from the dividend, attach it to 66 and continue: 660 / 90

Going ahead to step 6:
The number 90 fits into 660 7 times, leaving a remainder of 30.
The number 7 becomes the next digit in our result. 
Result so far: 7637.0
Deduct 630 from 660 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 7:
90 can be fit into 300 3 times, resulting in a remainder of 30.
The next digit of our result is 3. 
Result so far: 7637.3
Subtract 270 from 300 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 8:
300 divided by 90 is 3 with a remainder of 30.
The number 3 becomes the next digit in our result. 
Result so far: 7637.33
Deduct 270 from 300 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Our division results in 7637.33 with a remaining 0.03.