521221 ÷ 45 
Our goal is to divide 521221 by 45.

Step 1:
5 divided by 45 is 0 with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Include the next digit (2) from the dividend after 5, then repeat: 52 / 45

Advancing to step 2:
When dividing 52 by 45, we get 1 with a remainder of 7.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 45 away from 52, we end up with 7.
Include the next digit (1) from the dividend after 7, then repeat: 71 / 45

Moving on to step 3:
If we divide 71 by 45, we get 1 and a remainder of 26.
The next digit of our result is 1. 
Result so far: 11.0
Subtract 45 from 71 to get 26.
Take the next digit (2) from the dividend and append it to 26, then repeat: 262 / 45

Let's proceed to step 4:
When dividing 262 by 45, we get 5 with a remainder of 37.
The number 5 becomes the next digit in our result. 
Result so far: 115.0
Subtracting 225 from 262 leaves us with 37.
Bring next digit (2) of the dividend behind the 37 and repeat the process: 372 / 45

Moving on to step 5:
372 divided by 45 is 8 with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 1158.0
Subtract 360 from 372 to get 12.
Fetch the next digit (1) from the dividend, attach it to 12 and continue: 121 / 45

Moving on to step 6:
The number 45 fits into 121 2 times, leaving a remainder of 31.
Put 2 as the next digit of the answer. 
Result so far: 11582.0
If we take 90 away from 121, we end up with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

On to step 7:
If we divide 310 by 45, we get 6 and a remainder of 40.
The number 6 becomes the next digit in our result. 
Result so far: 11582.6
Subtracting 270 from 310 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 8:
45 goes into 400 8 times with a remainder of 40.
Use 8 as the next digit of our solution. 
Result so far: 11582.68
The remainder is 40 after subtracting 360 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 9:
When dividing 400 by 45, we get 8 with a remainder of 40.
Use 8 as the next digit of our solution. 
Result so far: 11582.688
Subtracting 360 from 400 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Our division results in 11582.688 with a remaining 0.004.