We look at the division of 65638548 by 438 
The aim is to understand the frequency of 438 in 65638548.

Advancing to step 1:
When dividing 6 by 438, we get 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Include the next digit (5) from the dividend after 6, then repeat: 65 / 438

On to step 2:
The number 438 fits into 65 0 times, leaving a remainder of 65.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 65 after subtracting 0 from 65.
Grab the next digit (6) from the dividend, add it to 65, then carry on: 656 / 438

Moving on to step 3:
If we divide 656 by 438, we get 1 and a remainder of 218.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we take 438 away from 656, we end up with 218.
Grab the next digit (3) from the dividend, add it to 218, then carry on: 2183 / 438

Step 4:
2183 divided by 438 is 4 with a remainder of 431.
The next digit of our result is 4. 
Result so far: 14.0
The remainder is 431 after subtracting 1752 from 2183.
Grab the next digit (8) from the dividend, add it to 431, then carry on: 4318 / 438

Step 5:
If we divide 4318 by 438, we get 9 and a remainder of 376.
The number 9 becomes the next digit in our result. 
Result so far: 149.0
Subtract 3942 from 4318 to get 376.
Append the next digit (5) from the dividend to 376 and continue with: 3765 / 438

Moving on to step 6:
The number 438 fits into 3765 8 times, leaving a remainder of 261.
Record the quotient 8 as the next digit in the result. 
Result so far: 1498.0
The remainder is 261 after subtracting 3504 from 3765.
Append the next digit (4) from the dividend to 261 and continue with: 2614 / 438

On to step 7:
The number 438 fits into 2614 5 times, leaving a remainder of 424.
Record the quotient 5 as the next digit in the result. 
Result so far: 14985.0
If we take 2190 away from 2614, we end up with 424.
Append the next digit (8) from the dividend to 424 and continue with: 4248 / 438

On to step 8:
438 can be fit into 4248 9 times, resulting in a remainder of 306.
Record the quotient 9 as the next digit in the result. 
Result so far: 149859.0
The remainder is 306 after subtracting 3942 from 4248.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3060, and continue the process.

Step 9:
3060 divided by 438 is 6 with a remainder of 432.
Write down 6 as next digit of the result. 
Result so far: 149859.6
The remainder is 432 after subtracting 2628 from 3060.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4320, and continue the process.

Advancing to step 10:
When dividing 4320 by 438, we get 9 with a remainder of 378.
The next digit of our result is 9. 
Result so far: 149859.69
If we subtract 3942 from 4320, we get 378.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3780, and continue the process.

Going ahead to step 11:
If we divide 3780 by 438, we get 8 and a remainder of 276.
Write down 8 as next digit of the result. 
Result so far: 149859.698
If we take 3504 away from 3780, we end up with 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

Going ahead to step 12:
438 goes into 2760 6 times with a remainder of 132.
The number 6 becomes the next digit in our result. 
Result so far: 149859.6986
Subtract 2628 from 2760 to get 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

Going ahead to step 13:
If we divide 1320 by 438, we get 3 and a remainder of 6.
Record the quotient 3 as the next digit in the result. 
Result so far: 149859.69863
The remainder is 6 after subtracting 1314 from 1320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 14:
438 can be fit into 60 0 times, resulting in a remainder of 60.
Write down 0 as next digit of the result. 
Result so far: 149859.69863
If we subtract 0 from 60, we get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 15:
If we divide 600 by 438, we get 1 and a remainder of 162.
The next digit of our result is 1. 
Result so far: 149859.6986301
Subtract 438 from 600 to get 162.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1620, and continue the process.

Advancing to step 16:
If we divide 1620 by 438, we get 3 and a remainder of 306.
Write down 3 as next digit of the result. 
Result so far: 149859.69863013
Subtracting 1314 from 1620 leaves us with 306.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3060, and continue the process.

The final outcome is 149859.69863013, with a leftover of 3.06e-07.