521120 ÷ 3 
We want to figure out the number of times 521120 can be divided by 3.

Step 1:
When dividing 5 by 3, we get 1 with a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 3 from 5, we get 2.
Include the next digit (2) from the dividend after 2, then repeat: 22 / 3

Going ahead to step 2:
3 goes into 22 7 times with a remainder of 1.
Put 7 as the next digit of the answer. 
Result so far: 17.0
If we take 21 away from 22, we end up with 1.
Grab the next digit (1) from the dividend, add it to 1, then carry on: 11 / 3

Going ahead to step 3:
3 can be fit into 11 3 times, resulting in a remainder of 2.
Record the quotient 3 as the next digit in the result. 
Result so far: 173.0
If we take 9 away from 11, we end up with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 3

Moving on to step 4:
21 divided by 3 is 7 with a remainder of 0.
Write down 7 as next digit of the result. 
Result so far: 1737.0
The remainder is 0 after subtracting 21 from 21.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 3

On to step 5:
When dividing 2 by 3, we get 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 17370.0
If we take 0 away from 2, we end up with 2.
Grab the next digit (0) from the dividend, add it to 2, then carry on: 20 / 3

On to step 6:
3 goes into 20 6 times with a remainder of 2.
The next digit of our result is 6. 
Result so far: 173706.0
Subtracting 18 from 20 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
20 divided by 3 is 6 with a remainder of 2.
The next digit of our result is 6. 
Result so far: 173706.6
If we subtract 18 from 20, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 8:
The number 3 fits into 20 6 times, leaving a remainder of 2.
Put 6 as the next digit of the answer. 
Result so far: 173706.66
Subtract 18 from 20 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final result is 173706.66 with a remainder of 0.002.