We look at the division of 41621488 by 621 
The aim is to understand the frequency of 621 in 41621488.

Step 1:
If we divide 4 by 621, we get 0 and a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Include the next digit (1) from the dividend after 4, then repeat: 41 / 621

Let's proceed to step 2:
If we divide 41 by 621, we get 0 and a remainder of 41.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 41 leaves us with 41.
Append the next digit (6) from the dividend to 41 and continue with: 416 / 621

Moving on to step 3:
621 can be fit into 416 0 times, resulting in a remainder of 416.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 416 after subtracting 0 from 416.
Include the next digit (2) from the dividend after 416, then repeat: 4162 / 621

Moving on to step 4:
When dividing 4162 by 621, we get 6 with a remainder of 436.
The next digit of our result is 6. 
Result so far: 6.0
Subtract 3726 from 4162 to get 436.
Append the next digit (1) from the dividend to 436 and continue with: 4361 / 621

Advancing to step 5:
621 goes into 4361 7 times with a remainder of 14.
Put 7 as the next digit of the answer. 
Result so far: 67.0
Subtracting 4347 from 4361 leaves us with 14.
Bring next digit (4) of the dividend behind the 14 and repeat the process: 144 / 621

Advancing to step 6:
If we divide 144 by 621, we get 0 and a remainder of 144.
The next digit of our result is 0. 
Result so far: 670.0
If we take 0 away from 144, we end up with 144.
Include the next digit (8) from the dividend after 144, then repeat: 1448 / 621

Advancing to step 7:
The number 621 fits into 1448 2 times, leaving a remainder of 206.
The number 2 becomes the next digit in our result. 
Result so far: 6702.0
The remainder is 206 after subtracting 1242 from 1448.
Include the next digit (8) from the dividend after 206, then repeat: 2068 / 621

Advancing to step 8:
The number 621 fits into 2068 3 times, leaving a remainder of 205.
Write down 3 as next digit of the result. 
Result so far: 67023.0
If we subtract 1863 from 2068, we get 205.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2050, and continue the process.

Step 9:
When dividing 2050 by 621, we get 3 with a remainder of 187.
The number 3 becomes the next digit in our result. 
Result so far: 67023.3
If we subtract 1863 from 2050, we get 187.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1870, and continue the process.

Step 10:
621 can be fit into 1870 3 times, resulting in a remainder of 7.
Use 3 as the next digit of our solution. 
Result so far: 67023.33
If we subtract 1863 from 1870, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final outcome is 67023.33, with a leftover of 0.007.