We're dividing 53904 by 40 
The aim is to understand the frequency of 40 in 53904.

Step 1:
40 goes into 5 0 times with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Grab the next digit (3) from the dividend, add it to 5, then carry on: 53 / 40

On to step 2:
The number 40 fits into 53 1 times, leaving a remainder of 13.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
The remainder is 13 after subtracting 40 from 53.
Include the next digit (9) from the dividend after 13, then repeat: 139 / 40

Step 3:
The number 40 fits into 139 3 times, leaving a remainder of 19.
The next digit of our result is 3. 
Result so far: 13.0
The remainder is 19 after subtracting 120 from 139.
Include the next digit (0) from the dividend after 19, then repeat: 190 / 40

Let's proceed to step 4:
190 divided by 40 is 4 with a remainder of 30.
Record the quotient 4 as the next digit in the result. 
Result so far: 134.0
Deduct 160 from 190 and we're left with 30.
Take the next digit (4) from the dividend and append it to 30, then repeat: 304 / 40

Step 5:
304 divided by 40 is 7 with a remainder of 24.
Put 7 as the next digit of the answer. 
Result so far: 1347.0
Deduct 280 from 304 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Step 6:
40 goes into 240 6 times with a remainder of 0.
The next digit of our result is 6. 
Result so far: 1347.6
The remainder is 0 after subtracting 240 from 240.
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 7:
The number 40 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 1347.6
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.

Step 8:
If we divide 0 by 40, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 1347.6
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.

Our division results in 1347.6 with a remaining 0.0.