We look at the division of 663974 by 40 
We're looking to find how many times 40 goes into 663974.

On to step 1:
When dividing 6 by 40, we get 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 40

On to step 2:
If we divide 66 by 40, we get 1 and a remainder of 26.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 40 from 66 and we're left with 26.
Include the next digit (3) from the dividend after 26, then repeat: 263 / 40

Advancing to step 3:
If we divide 263 by 40, we get 6 and a remainder of 23.
The number 6 becomes the next digit in our result. 
Result so far: 16.0
If we subtract 240 from 263, we get 23.
Fetch the next digit (9) from the dividend, attach it to 23 and continue: 239 / 40

Going ahead to step 4:
When dividing 239 by 40, we get 5 with a remainder of 39.
Write down 5 as next digit of the result. 
Result so far: 165.0
If we subtract 200 from 239, we get 39.
Take the next digit (7) from the dividend and append it to 39, then repeat: 397 / 40

Let's proceed to step 5:
When dividing 397 by 40, we get 9 with a remainder of 37.
The next digit of our result is 9. 
Result so far: 1659.0
Subtract 360 from 397 to get 37.
Bring next digit (4) of the dividend behind the 37 and repeat the process: 374 / 40

Step 6:
40 can be fit into 374 9 times, resulting in a remainder of 14.
The number 9 becomes the next digit in our result. 
Result so far: 16599.0
Subtracting 360 from 374 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 7:
40 goes into 140 3 times with a remainder of 20.
Write down 3 as next digit of the result. 
Result so far: 16599.3
Deduct 120 from 140 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.

Advancing to step 8:
40 goes into 200 5 times with a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 16599.35
Subtract 200 from 200 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 9:
40 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 16599.35
If we subtract 0 from 0, 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.

Step 10:
40 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 16599.35
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 16599.35 with a remaining 0.0.