We're dividing 521392 by 87 
We want to figure out the number of times 521392 can be divided by 87.

Advancing to step 1:
5 divided by 87 is 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Fetch the next digit (2) from the dividend, attach it to 5 and continue: 52 / 87

Advancing to step 2:
When dividing 52 by 87, we get 0 with a remainder of 52.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 52 to get 52.
Append the next digit (1) from the dividend to 52 and continue with: 521 / 87

Going ahead to step 3:
If we divide 521 by 87, we get 5 and a remainder of 86.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
Subtracting 435 from 521 leaves us with 86.
Take the next digit (3) from the dividend and append it to 86, then repeat: 863 / 87

Going ahead to step 4:
If we divide 863 by 87, we get 9 and a remainder of 80.
Use 9 as the next digit of our solution. 
Result so far: 59.0
If we take 783 away from 863, we end up with 80.
Append the next digit (9) from the dividend to 80 and continue with: 809 / 87

Step 5:
87 can be fit into 809 9 times, resulting in a remainder of 26.
Write down 9 as next digit of the result. 
Result so far: 599.0
The remainder is 26 after subtracting 783 from 809.
Take the next digit (2) from the dividend and append it to 26, then repeat: 262 / 87

Step 6:
If we divide 262 by 87, we get 3 and a remainder of 1.
Record the quotient 3 as the next digit in the result. 
Result so far: 5993.0
The remainder is 1 after subtracting 261 from 262.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 7:
87 can be fit into 10 0 times, resulting in a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 5993.0
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 8:
100 divided by 87 is 1 with a remainder of 13.
Use 1 as the next digit of our solution. 
Result so far: 5993.01
Subtracting 87 from 100 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 9:
87 goes into 130 1 times with a remainder of 43.
The number 1 becomes the next digit in our result. 
Result so far: 5993.011
Subtracting 87 from 130 leaves us with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Our division results in 5993.011 with a remaining 0.0043.