We're dividing 646001 by 40 
We want to figure out the number of times 646001 can be divided by 40.

On to step 1:
The number 40 fits into 6 0 times, leaving a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 40

On to step 2:
When dividing 64 by 40, we get 1 with a remainder of 24.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 40 from 64 and we're left with 24.
Bring next digit (6) of the dividend behind the 24 and repeat the process: 246 / 40

Step 3:
246 divided by 40 is 6 with a remainder of 6.
Put 6 as the next digit of the answer. 
Result so far: 16.0
Subtracting 240 from 246 leaves us with 6.
Bring next digit (0) of the dividend behind the 6 and repeat the process: 60 / 40

On to step 4:
When dividing 60 by 40, we get 1 with a remainder of 20.
The number 1 becomes the next digit in our result. 
Result so far: 161.0
Subtracting 40 from 60 leaves us with 20.
Fetch the next digit (0) from the dividend, attach it to 20 and continue: 200 / 40

Step 5:
40 goes into 200 5 times with a remainder of 0.
The next digit of our result is 5. 
Result so far: 1615.0
If we subtract 200 from 200, we get 0.
Fetch the next digit (1) from the dividend, attach it to 0 and continue: 1 / 40

Moving on to step 6:
When dividing 1 by 40, we get 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 16150.0
Subtracting 0 from 1 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 7:
The number 40 fits into 10 0 times, leaving a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 16150.0
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 8:
40 goes into 100 2 times with a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 16150.02
Deduct 80 from 100 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 9:
The number 40 fits into 200 5 times, leaving a remainder of 0.
The next digit of our result is 5. 
Result so far: 16150.025
The remainder is 0 after subtracting 200 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 10:
If we divide 0 by 40, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 16150.025
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.

Advancing to step 11:
0 divided by 40 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 16150.025
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.

The final result is 16150.025 with a remainder of 0.0.