90245457 ÷ 399 
We're looking to find how many times 399 goes into 90245457.

Moving on to step 1:
If we divide 9 by 399, we get 0 and a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Grab the next digit (0) from the dividend, add it to 9, then carry on: 90 / 399

Advancing to step 2:
If we divide 90 by 399, we get 0 and a remainder of 90.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 90, we get 90.
Fetch the next digit (2) from the dividend, attach it to 90 and continue: 902 / 399

Going ahead to step 3:
When dividing 902 by 399, we get 2 with a remainder of 104.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we subtract 798 from 902, we get 104.
Fetch the next digit (4) from the dividend, attach it to 104 and continue: 1044 / 399

Moving on to step 4:
399 goes into 1044 2 times with a remainder of 246.
Record the quotient 2 as the next digit in the result. 
Result so far: 22.0
Subtract 798 from 1044 to get 246.
Fetch the next digit (5) from the dividend, attach it to 246 and continue: 2465 / 399

On to step 5:
399 goes into 2465 6 times with a remainder of 71.
Put 6 as the next digit of the answer. 
Result so far: 226.0
Deduct 2394 from 2465 and we're left with 71.
Fetch the next digit (4) from the dividend, attach it to 71 and continue: 714 / 399

Let's proceed to step 6:
714 divided by 399 is 1 with a remainder of 315.
The next digit of our result is 1. 
Result so far: 2261.0
Subtract 399 from 714 to get 315.
Take the next digit (5) from the dividend and append it to 315, then repeat: 3155 / 399

On to step 7:
When dividing 3155 by 399, we get 7 with a remainder of 362.
The number 7 becomes the next digit in our result. 
Result so far: 22617.0
Deduct 2793 from 3155 and we're left with 362.
Append the next digit (7) from the dividend to 362 and continue with: 3627 / 399

Moving on to step 8:
399 can be fit into 3627 9 times, resulting in a remainder of 36.
Record the quotient 9 as the next digit in the result. 
Result so far: 226179.0
If we take 3591 away from 3627, we end up with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Advancing to step 9:
If we divide 360 by 399, we get 0 and a remainder of 360.
Write down 0 as next digit of the result. 
Result so far: 226179.0
Subtracting 0 from 360 leaves us with 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Going ahead to step 10:
If we divide 3600 by 399, we get 9 and a remainder of 9.
Record the quotient 9 as the next digit in the result. 
Result so far: 226179.09
If we take 3591 away from 3600, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 11:
90 divided by 399 is 0 with a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 226179.09
If we subtract 0 from 90, we get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Going ahead to step 12:
When dividing 900 by 399, we get 2 with a remainder of 102.
Put 2 as the next digit of the answer. 
Result so far: 226179.0902
Deduct 798 from 900 and we're left with 102.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1020, and continue the process.

Going ahead to step 13:
When dividing 1020 by 399, we get 2 with a remainder of 222.
Write down 2 as next digit of the result. 
Result so far: 226179.09022
Subtract 798 from 1020 to get 222.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2220, and continue the process.

The final outcome is 226179.09022, with a leftover of 0.000222.