We're dividing 1258336 by 399 
Our goal is to divide 1258336 by 399.

On to step 1:
399 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 399

Going ahead to step 2:
If we divide 12 by 399, we get 0 and a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Fetch the next digit (5) from the dividend, attach it to 12 and continue: 125 / 399

Advancing to step 3:
399 can be fit into 125 0 times, resulting in a remainder of 125.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 125 leaves us with 125.
Bring next digit (8) of the dividend behind the 125 and repeat the process: 1258 / 399

Step 4:
399 can be fit into 1258 3 times, resulting in a remainder of 61.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we subtract 1197 from 1258, we get 61.
Take the next digit (3) from the dividend and append it to 61, then repeat: 613 / 399

Advancing to step 5:
399 can be fit into 613 1 times, resulting in a remainder of 214.
Put 1 as the next digit of the answer. 
Result so far: 31.0
Subtracting 399 from 613 leaves us with 214.
Append the next digit (3) from the dividend to 214 and continue with: 2143 / 399

Step 6:
If we divide 2143 by 399, we get 5 and a remainder of 148.
Put 5 as the next digit of the answer. 
Result so far: 315.0
The remainder is 148 after subtracting 1995 from 2143.
Include the next digit (6) from the dividend after 148, then repeat: 1486 / 399

Going ahead to step 7:
When dividing 1486 by 399, we get 3 with a remainder of 289.
Use 3 as the next digit of our solution. 
Result so far: 3153.0
Subtract 1197 from 1486 to get 289.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2890, and continue the process.

Going ahead to step 8:
2890 divided by 399 is 7 with a remainder of 97.
The next digit of our result is 7. 
Result so far: 3153.7
Subtract 2793 from 2890 to get 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Moving on to step 9:
When dividing 970 by 399, we get 2 with a remainder of 172.
Write down 2 as next digit of the result. 
Result so far: 3153.72
The remainder is 172 after subtracting 798 from 970.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1720, and continue the process.

Going ahead to step 10:
When dividing 1720 by 399, we get 4 with a remainder of 124.
The next digit of our result is 4. 
Result so far: 3153.724
If we take 1596 away from 1720, we end up with 124.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1240, and continue the process.

Step 11:
399 goes into 1240 3 times with a remainder of 43.
Record the quotient 3 as the next digit in the result. 
Result so far: 3153.7243
The remainder is 43 after subtracting 1197 from 1240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Let's proceed to step 12:
399 can be fit into 430 1 times, resulting in a remainder of 31.
Write down 1 as next digit of the result. 
Result so far: 3153.72431
Subtracting 399 from 430 leaves us 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.

Moving on to step 13:
If we divide 310 by 399, we get 0 and a remainder of 310.
Put 0 as the next digit of the answer. 
Result so far: 3153.72431
If we subtract 0 from 310, we get 310.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3100, and continue the process.

Let's proceed to step 14:
The number 399 fits into 3100 7 times, leaving a remainder of 307.
The next digit of our result is 7. 
Result so far: 3153.7243107
Subtracting 2793 from 3100 leaves us with 307.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3070, and continue the process.

Step 15:
399 goes into 3070 7 times with a remainder of 277.
Write down 7 as next digit of the result. 
Result so far: 3153.72431077
If we take 2793 away from 3070, we end up with 277.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2770, and continue the process.

After the division, we end up with 3153.72431077 and a remainder of 2.77e-07.