We look at the division of 866580 by 16 
We're looking to find how many times 16 goes into 866580.

Step 1:
8 divided by 16 is 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Grab the next digit (6) from the dividend, add it to 8, then carry on: 86 / 16

Step 2:
When dividing 86 by 16, we get 5 with a remainder of 6.
Use 5 as the next digit of our solution. 
Result so far: 5.0
If we take 80 away from 86, we end up with 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 16

On to step 3:
When dividing 66 by 16, we get 4 with a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 54.0
The remainder is 2 after subtracting 64 from 66.
Grab the next digit (5) from the dividend, add it to 2, then carry on: 25 / 16

Going ahead to step 4:
The number 16 fits into 25 1 times, leaving a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 541.0
The remainder is 9 after subtracting 16 from 25.
Append the next digit (8) from the dividend to 9 and continue with: 98 / 16

Advancing to step 5:
16 goes into 98 6 times with a remainder of 2.
Record the quotient 6 as the next digit in the result. 
Result so far: 5416.0
Subtract 96 from 98 to get 2.
Append the next digit (0) from the dividend to 2 and continue with: 20 / 16

Going ahead to step 6:
When dividing 20 by 16, we get 1 with a remainder of 4.
Put 1 as the next digit of the answer. 
Result so far: 54161.0
Subtract 16 from 20 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 7:
The number 16 fits into 40 2 times, leaving a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 54161.2
The remainder is 8 after subtracting 32 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 8:
The number 16 fits into 80 5 times, leaving a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 54161.25
If we take 80 away from 80, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 9:
16 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 54161.25
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 10:
If we divide 0 by 16, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 54161.25
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 54161.25 with a remainder of 0.0.