We're dividing 521390 by 10 
We want to figure out the number of times 521390 can be divided by 10.

On to step 1:
If we divide 5 by 10, we get 0 and a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Include the next digit (2) from the dividend after 5, then repeat: 52 / 10

On to step 2:
The number 10 fits into 52 5 times, leaving a remainder of 2.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
Deduct 50 from 52 and we're left with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 10

Moving on to step 3:
When dividing 21 by 10, we get 2 with a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 52.0
If we take 20 away from 21, we end up with 1.
Append the next digit (3) from the dividend to 1 and continue with: 13 / 10

Advancing to step 4:
10 goes into 13 1 times with a remainder of 3.
Write down 1 as next digit of the result. 
Result so far: 521.0
If we take 10 away from 13, we end up with 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 10

Let's proceed to step 5:
If we divide 39 by 10, we get 3 and a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 5213.0
Subtract 30 from 39 to get 9.
Append the next digit (0) from the dividend to 9 and continue with: 90 / 10

Advancing to step 6:
The number 10 fits into 90 9 times, leaving a remainder of 0.
Write down 9 as next digit of the result. 
Result so far: 52139.0
Subtract 90 from 90 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 7:
10 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: 52139.0
Subtract 0 from 0 to get 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 8:
The number 10 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 52139.0
Subtracting 0 from 0 leaves us 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.

Our division results in 52139.0 with a remaining 0.0.