We're dividing 12182451 by 225 
Let's see how many times 225 fits into 12182451.

Step 1:
225 goes into 1 0 times with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Take the next digit (2) from the dividend and append it to 1, then repeat: 12 / 225

On to step 2:
If we divide 12 by 225, we get 0 and a remainder of 12.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 12, we end up with 12.
Take the next digit (1) from the dividend and append it to 12, then repeat: 121 / 225

Step 3:
225 can be fit into 121 0 times, resulting in a remainder of 121.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 121, we end up with 121.
Take the next digit (8) from the dividend and append it to 121, then repeat: 1218 / 225

On to step 4:
225 goes into 1218 5 times with a remainder of 93.
Use 5 as the next digit of our solution. 
Result so far: 5.0
The remainder is 93 after subtracting 1125 from 1218.
Take the next digit (2) from the dividend and append it to 93, then repeat: 932 / 225

On to step 5:
When dividing 932 by 225, we get 4 with a remainder of 32.
Write down 4 as next digit of the result. 
Result so far: 54.0
If we subtract 900 from 932, we get 32.
Grab the next digit (4) from the dividend, add it to 32, then carry on: 324 / 225

Moving on to step 6:
225 goes into 324 1 times with a remainder of 99.
The next digit of our result is 1. 
Result so far: 541.0
If we take 225 away from 324, we end up with 99.
Take the next digit (5) from the dividend and append it to 99, then repeat: 995 / 225

Going ahead to step 7:
995 divided by 225 is 4 with a remainder of 95.
The number 4 becomes the next digit in our result. 
Result so far: 5414.0
If we take 900 away from 995, we end up with 95.
Fetch the next digit (1) from the dividend, attach it to 95 and continue: 951 / 225

On to step 8:
If we divide 951 by 225, we get 4 and a remainder of 51.
The next digit of our result is 4. 
Result so far: 54144.0
If we subtract 900 from 951, we get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

On to step 9:
When dividing 510 by 225, we get 2 with a remainder of 60.
The next digit of our result is 2. 
Result so far: 54144.2
The remainder is 60 after subtracting 450 from 510.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 10:
225 goes into 600 2 times with a remainder of 150.
The number 2 becomes the next digit in our result. 
Result so far: 54144.22
Deduct 450 from 600 and we're left with 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

The final result is 54144.22 with a remainder of 0.15.