We look at the division of 40339442 by 646 
The aim is to understand the frequency of 646 in 40339442.

On to step 1:
If we divide 4 by 646, we get 0 and a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Grab the next digit (0) from the dividend, add it to 4, then carry on: 40 / 646

On to step 2:
646 can be fit into 40 0 times, resulting in a remainder of 40.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 40 and we're left with 40.
Include the next digit (3) from the dividend after 40, then repeat: 403 / 646

Moving on to step 3:
403 divided by 646 is 0 with a remainder of 403.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 403, we end up with 403.
Fetch the next digit (3) from the dividend, attach it to 403 and continue: 4033 / 646

Advancing to step 4:
646 can be fit into 4033 6 times, resulting in a remainder of 157.
Use 6 as the next digit of our solution. 
Result so far: 6.0
If we subtract 3876 from 4033, we get 157.
Take the next digit (9) from the dividend and append it to 157, then repeat: 1579 / 646

Going ahead to step 5:
646 goes into 1579 2 times with a remainder of 287.
Put 2 as the next digit of the answer. 
Result so far: 62.0
Subtract 1292 from 1579 to get 287.
Append the next digit (4) from the dividend to 287 and continue with: 2874 / 646

On to step 6:
2874 divided by 646 is 4 with a remainder of 290.
Put 4 as the next digit of the answer. 
Result so far: 624.0
The remainder is 290 after subtracting 2584 from 2874.
Bring next digit (4) of the dividend behind the 290 and repeat the process: 2904 / 646

Step 7:
When dividing 2904 by 646, we get 4 with a remainder of 320.
Write down 4 as next digit of the result. 
Result so far: 6244.0
The remainder is 320 after subtracting 2584 from 2904.
Take the next digit (2) from the dividend and append it to 320, then repeat: 3202 / 646

Going ahead to step 8:
646 can be fit into 3202 4 times, resulting in a remainder of 618.
The next digit of our result is 4. 
Result so far: 62444.0
Subtracting 2584 from 3202 leaves us with 618.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6180, and continue the process.

Advancing to step 9:
The number 646 fits into 6180 9 times, leaving a remainder of 366.
Write down 9 as next digit of the result. 
Result so far: 62444.9
Subtracting 5814 from 6180 leaves us with 366.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3660, and continue the process.

Step 10:
3660 divided by 646 is 5 with a remainder of 430.
The next digit of our result is 5. 
Result so far: 62444.95
Subtract 3230 from 3660 to get 430.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4300, and continue the process.

Step 11:
4300 divided by 646 is 6 with a remainder of 424.
Put 6 as the next digit of the answer. 
Result so far: 62444.956
Subtracting 3876 from 4300 leaves us with 424.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4240, and continue the process.

Going ahead to step 12:
646 can be fit into 4240 6 times, resulting in a remainder of 364.
Write down 6 as next digit of the result. 
Result so far: 62444.9566
If we take 3876 away from 4240, we end up with 364.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3640, and continue the process.

Our division results in 62444.9566 with a remaining 0.00364.