646172 divided by 40 
Our goal is to divide 646172 by 40.

Step 1:
The number 40 fits into 6 0 times, leaving a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Include the next digit (4) from the dividend after 6, then repeat: 64 / 40

Going ahead to step 2:
When dividing 64 by 40, we get 1 with a remainder of 24.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 40 from 64 and we're left with 24.
Take the next digit (6) from the dividend and append it to 24, then repeat: 246 / 40

Moving on to step 3:
246 divided by 40 is 6 with a remainder of 6.
The next digit of our result is 6. 
Result so far: 16.0
The remainder is 6 after subtracting 240 from 246.
Bring next digit (1) of the dividend behind the 6 and repeat the process: 61 / 40

Let's proceed to step 4:
40 can be fit into 61 1 times, resulting in a remainder of 21.
Use 1 as the next digit of our solution. 
Result so far: 161.0
Subtracting 40 from 61 leaves us with 21.
Fetch the next digit (7) from the dividend, attach it to 21 and continue: 217 / 40

Step 5:
The number 40 fits into 217 5 times, leaving a remainder of 17.
Write down 5 as next digit of the result. 
Result so far: 1615.0
Subtract 200 from 217 to get 17.
Append the next digit (2) from the dividend to 17 and continue with: 172 / 40

Let's proceed to step 6:
When dividing 172 by 40, we get 4 with a remainder of 12.
The number 4 becomes the next digit in our result. 
Result so far: 16154.0
If we take 160 away from 172, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 7:
The number 40 fits into 120 3 times, leaving a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 16154.3
If we subtract 120 from 120, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 8:
40 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 16154.3
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 9:
The number 40 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 16154.3
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 16154.3 and a remainder of 0.0.