We divide 643421 by 64
The aim is to understand the frequency of 64 in 643421.

Let's proceed to step 1:
6 divided by 64 is 0 with a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 64

Moving on to step 2:
The number 64 fits into 64 1 times, leaving a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 64 from 64, we get 0.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 64

Let's proceed to step 3:
64 can be fit into 3 0 times, resulting in a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
Subtract 0 from 3 to get 3.
Grab the next digit (4) from the dividend, add it to 3, then carry on: 34 / 64

On to step 4:
64 goes into 34 0 times with a remainder of 34.
Record the quotient 0 as the next digit in the result. 
Result so far: 100.0
If we take 0 away from 34, we end up with 34.
Take the next digit (2) from the dividend and append it to 34, then repeat: 342 / 64

Advancing to step 5:
64 can be fit into 342 5 times, resulting in a remainder of 22.
The number 5 becomes the next digit in our result. 
Result so far: 1005.0
If we take 320 away from 342, we end up with 22.
Include the next digit (1) from the dividend after 22, then repeat: 221 / 64

On to step 6:
If we divide 221 by 64, we get 3 and a remainder of 29.
The next digit of our result is 3. 
Result so far: 10053.0
Subtract 192 from 221 to get 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Advancing to step 7:
If we divide 290 by 64, we get 4 and a remainder of 34.
The number 4 becomes the next digit in our result. 
Result so far: 10053.4
Subtracting 256 from 290 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

On to step 8:
If we divide 340 by 64, we get 5 and a remainder of 20.
Record the quotient 5 as the next digit in the result. 
Result so far: 10053.45
If we take 320 away from 340, we end up 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.

Moving on to step 9:
200 divided by 64 is 3 with a remainder of 8.
Write down 3 as next digit of the result. 
Result so far: 10053.453
Subtracting 192 from 200 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 10:
When dividing 80 by 64, we get 1 with a remainder of 16.
The next digit of our result is 1. 
Result so far: 10053.4531
If we take 64 away from 80, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 11:
160 divided by 64 is 2 with a remainder of 32.
Write down 2 as next digit of the result. 
Result so far: 10053.45312
The remainder is 32 after subtracting 128 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

On to step 12:
64 goes into 320 5 times with a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 10053.453125
Deduct 320 from 320 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 13:
If we divide 0 by 64, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 10053.453125
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 14:
0 divided by 64 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 10053.453125
If we take 0 away from 0, we end up with 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 10053.453125 with a remaining 0.0.