20402413 ÷ 646 
Our goal is to divide 20402413 by 646.

Moving on to step 1:
2 divided by 646 is 0 with a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Grab the next digit (0) from the dividend, add it to 2, then carry on: 20 / 646

Moving on to step 2:
The number 646 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 20 after subtracting 0 from 20.
Take the next digit (4) from the dividend and append it to 20, then repeat: 204 / 646

Going ahead to step 3:
646 goes into 204 0 times with a remainder of 204.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 204, we get 204.
Bring next digit (0) of the dividend behind the 204 and repeat the process: 2040 / 646

Going ahead to step 4:
The number 646 fits into 2040 3 times, leaving a remainder of 102.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Deduct 1938 from 2040 and we're left with 102.
Include the next digit (2) from the dividend after 102, then repeat: 1022 / 646

Step 5:
646 goes into 1022 1 times with a remainder of 376.
The next digit of our result is 1. 
Result so far: 31.0
Deduct 646 from 1022 and we're left with 376.
Grab the next digit (4) from the dividend, add it to 376, then carry on: 3764 / 646

Let's proceed to step 6:
646 can be fit into 3764 5 times, resulting in a remainder of 534.
The next digit of our result is 5. 
Result so far: 315.0
Subtracting 3230 from 3764 leaves us with 534.
Grab the next digit (1) from the dividend, add it to 534, then carry on: 5341 / 646

Step 7:
646 can be fit into 5341 8 times, resulting in a remainder of 173.
Use 8 as the next digit of our solution. 
Result so far: 3158.0
The remainder is 173 after subtracting 5168 from 5341.
Bring next digit (3) of the dividend behind the 173 and repeat the process: 1733 / 646

Let's proceed to step 8:
When dividing 1733 by 646, we get 2 with a remainder of 441.
Record the quotient 2 as the next digit in the result. 
Result so far: 31582.0
Subtract 1292 from 1733 to get 441.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4410, and continue the process.

Going ahead to step 9:
If we divide 4410 by 646, we get 6 and a remainder of 534.
Record the quotient 6 as the next digit in the result. 
Result so far: 31582.6
If we subtract 3876 from 4410, we get 534.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5340, and continue the process.

On to step 10:
When dividing 5340 by 646, we get 8 with a remainder of 172.
Put 8 as the next digit of the answer. 
Result so far: 31582.68
Deduct 5168 from 5340 and we're left with 172.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1720, and continue the process.

Advancing to step 11:
646 can be fit into 1720 2 times, resulting in a remainder of 428.
Write down 2 as next digit of the result. 
Result so far: 31582.682
Deduct 1292 from 1720 and we're left with 428.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4280, and continue the process.

Moving on to step 12:
4280 divided by 646 is 6 with a remainder of 404.
Write down 6 as next digit of the result. 
Result so far: 31582.6826
The remainder is 404 after subtracting 3876 from 4280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4040, and continue the process.

Step 13:
646 can be fit into 4040 6 times, resulting in a remainder of 164.
Record the quotient 6 as the next digit in the result. 
Result so far: 31582.68266
The remainder is 164 after subtracting 3876 from 4040.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1640, and continue the process.

Our division results in 31582.68266 with a remaining 0.000164.