72893180 ÷ 644 
The aim is to understand the frequency of 644 in 72893180.

Moving on to step 1:
7 divided by 644 is 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Grab the next digit (2) from the dividend, add it to 7, then carry on: 72 / 644

Let's proceed to step 2:
When dividing 72 by 644, we get 0 with a remainder of 72.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 72 and we're left with 72.
Take the next digit (8) from the dividend and append it to 72, then repeat: 728 / 644

Let's proceed to step 3:
If we divide 728 by 644, we get 1 and a remainder of 84.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 84 after subtracting 644 from 728.
Take the next digit (9) from the dividend and append it to 84, then repeat: 849 / 644

Advancing to step 4:
When dividing 849 by 644, we get 1 with a remainder of 205.
Write down 1 as next digit of the result. 
Result so far: 11.0
Deduct 644 from 849 and we're left with 205.
Append the next digit (3) from the dividend to 205 and continue with: 2053 / 644

Step 5:
644 can be fit into 2053 3 times, resulting in a remainder of 121.
The next digit of our result is 3. 
Result so far: 113.0
The remainder is 121 after subtracting 1932 from 2053.
Fetch the next digit (1) from the dividend, attach it to 121 and continue: 1211 / 644

Advancing to step 6:
1211 divided by 644 is 1 with a remainder of 567.
The number 1 becomes the next digit in our result. 
Result so far: 1131.0
Subtracting 644 from 1211 leaves us with 567.
Bring next digit (8) of the dividend behind the 567 and repeat the process: 5678 / 644

Step 7:
When dividing 5678 by 644, we get 8 with a remainder of 526.
Put 8 as the next digit of the answer. 
Result so far: 11318.0
Subtract 5152 from 5678 to get 526.
Bring next digit (0) of the dividend behind the 526 and repeat the process: 5260 / 644

Moving on to step 8:
When dividing 5260 by 644, we get 8 with a remainder of 108.
The next digit of our result is 8. 
Result so far: 113188.0
The remainder is 108 after subtracting 5152 from 5260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Let's proceed to step 9:
1080 divided by 644 is 1 with a remainder of 436.
The number 1 becomes the next digit in our result. 
Result so far: 113188.1
Subtracting 644 from 1080 leaves us with 436.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4360, and continue the process.

Moving on to step 10:
If we divide 4360 by 644, we get 6 and a remainder of 496.
The number 6 becomes the next digit in our result. 
Result so far: 113188.16
Deduct 3864 from 4360 and we're left with 496.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4960, and continue the process.

Step 11:
When dividing 4960 by 644, we get 7 with a remainder of 452.
The number 7 becomes the next digit in our result. 
Result so far: 113188.167
If we subtract 4508 from 4960, we get 452.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4520, and continue the process.

Going ahead to step 12:
644 goes into 4520 7 times with a remainder of 12.
Record the quotient 7 as the next digit in the result. 
Result so far: 113188.1677
If we take 4508 away from 4520, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Our division results in 113188.1677 with a remaining 0.00012.