We divide 664989 by 87
The aim is to understand the frequency of 87 in 664989.

On to step 1:
If we divide 6 by 87, we get 0 and a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 87

Step 2:
The number 87 fits into 66 0 times, leaving a remainder of 66.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Append the next digit (4) from the dividend to 66 and continue with: 664 / 87

Going ahead to step 3:
When dividing 664 by 87, we get 7 with a remainder of 55.
Put 7 as the next digit of the answer. 
Result so far: 7.0
If we take 609 away from 664, we end up with 55.
Append the next digit (9) from the dividend to 55 and continue with: 559 / 87

Going ahead to step 4:
87 goes into 559 6 times with a remainder of 37.
Record the quotient 6 as the next digit in the result. 
Result so far: 76.0
If we subtract 522 from 559, we get 37.
Bring next digit (8) of the dividend behind the 37 and repeat the process: 378 / 87

On to step 5:
87 can be fit into 378 4 times, resulting in a remainder of 30.
The number 4 becomes the next digit in our result. 
Result so far: 764.0
If we subtract 348 from 378, we get 30.
Bring next digit (9) of the dividend behind the 30 and repeat the process: 309 / 87

Moving on to step 6:
The number 87 fits into 309 3 times, leaving a remainder of 48.
The number 3 becomes the next digit in our result. 
Result so far: 7643.0
Subtract 261 from 309 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Moving on to step 7:
The number 87 fits into 480 5 times, leaving a remainder of 45.
The number 5 becomes the next digit in our result. 
Result so far: 7643.5
Deduct 435 from 480 and we're left with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 8:
87 goes into 450 5 times with a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 7643.55
The remainder is 15 after subtracting 435 from 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final outcome is 7643.55, with a leftover of 0.015.