We're dividing 669431 by 40 
The aim is to understand the frequency of 40 in 669431.

Let's proceed to step 1:
If we divide 6 by 40, we get 0 and a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 40

On to step 2:
40 can be fit into 66 1 times, resulting in a remainder of 26.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 26 after subtracting 40 from 66.
Bring next digit (9) of the dividend behind the 26 and repeat the process: 269 / 40

Step 3:
When dividing 269 by 40, we get 6 with a remainder of 29.
Use 6 as the next digit of our solution. 
Result so far: 16.0
Deduct 240 from 269 and we're left with 29.
Take the next digit (4) from the dividend and append it to 29, then repeat: 294 / 40

Advancing to step 4:
40 goes into 294 7 times with a remainder of 14.
The number 7 becomes the next digit in our result. 
Result so far: 167.0
Subtracting 280 from 294 leaves us with 14.
Bring next digit (3) of the dividend behind the 14 and repeat the process: 143 / 40

On to step 5:
40 can be fit into 143 3 times, resulting in a remainder of 23.
Write down 3 as next digit of the result. 
Result so far: 1673.0
Subtract 120 from 143 to get 23.
Append the next digit (1) from the dividend to 23 and continue with: 231 / 40

Moving on to step 6:
The number 40 fits into 231 5 times, leaving a remainder of 31.
The number 5 becomes the next digit in our result. 
Result so far: 16735.0
If we subtract 200 from 231, we get 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

On to step 7:
If we divide 310 by 40, we get 7 and a remainder of 30.
The number 7 becomes the next digit in our result. 
Result so far: 16735.7
The remainder is 30 after subtracting 280 from 310.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 8:
When dividing 300 by 40, we get 7 with a remainder of 20.
The number 7 becomes the next digit in our result. 
Result so far: 16735.77
Deduct 280 from 300 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.

The final result is 16735.77 with a remainder of 0.02.