We divide 521009 by 86
We're looking to find how many times 86 goes into 521009.

Advancing to step 1:
86 can be fit into 5 0 times, resulting in a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Bring next digit (2) of the dividend behind the 5 and repeat the process: 52 / 86

Let's proceed to step 2:
86 goes into 52 0 times with a remainder of 52.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 52, we get 52.
Grab the next digit (1) from the dividend, add it to 52, then carry on: 521 / 86

Step 3:
86 goes into 521 6 times with a remainder of 5.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
If we subtract 516 from 521, we get 5.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 86

Advancing to step 4:
If we divide 50 by 86, we get 0 and a remainder of 50.
Put 0 as the next digit of the answer. 
Result so far: 60.0
Deduct 0 from 50 and we're left with 50.
Grab the next digit (0) from the dividend, add it to 50, then carry on: 500 / 86

Going ahead to step 5:
86 can be fit into 500 5 times, resulting in a remainder of 70.
Write down 5 as next digit of the result. 
Result so far: 605.0
Deduct 430 from 500 and we're left with 70.
Bring next digit (9) of the dividend behind the 70 and repeat the process: 709 / 86

Let's proceed to step 6:
If we divide 709 by 86, we get 8 and a remainder of 21.
Record the quotient 8 as the next digit in the result. 
Result so far: 6058.0
Deduct 688 from 709 and we're left with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 7:
The number 86 fits into 210 2 times, leaving a remainder of 38.
Use 2 as the next digit of our solution. 
Result so far: 6058.2
Deduct 172 from 210 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Let's proceed to step 8:
If we divide 380 by 86, we get 4 and a remainder of 36.
Write down 4 as next digit of the result. 
Result so far: 6058.24
Subtract 344 from 380 to get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 9:
When dividing 360 by 86, we get 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 6058.244
Deduct 344 from 360 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final outcome is 6058.244, with a leftover of 0.0016.