We divide 1386849 by 644
The aim is to understand the frequency of 644 in 1386849.

Let's proceed to step 1:
The number 644 fits into 1 0 times, leaving a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 644

Moving on to step 2:
644 can be fit into 13 0 times, resulting in a remainder of 13.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 13, we get 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 644

Step 3:
When dividing 138 by 644, we get 0 with a remainder of 138.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 138 to get 138.
Bring next digit (6) of the dividend behind the 138 and repeat the process: 1386 / 644

On to step 4:
When dividing 1386 by 644, we get 2 with a remainder of 98.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 1288 away from 1386, we end up with 98.
Take the next digit (8) from the dividend and append it to 98, then repeat: 988 / 644

Let's proceed to step 5:
644 can be fit into 988 1 times, resulting in a remainder of 344.
Use 1 as the next digit of our solution. 
Result so far: 21.0
Deduct 644 from 988 and we're left with 344.
Take the next digit (4) from the dividend and append it to 344, then repeat: 3444 / 644

Going ahead to step 6:
The number 644 fits into 3444 5 times, leaving a remainder of 224.
Put 5 as the next digit of the answer. 
Result so far: 215.0
Deduct 3220 from 3444 and we're left with 224.
Bring next digit (9) of the dividend behind the 224 and repeat the process: 2249 / 644

Going ahead to step 7:
When dividing 2249 by 644, we get 3 with a remainder of 317.
Use 3 as the next digit of our solution. 
Result so far: 2153.0
If we subtract 1932 from 2249, we get 317.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3170, and continue the process.

On to step 8:
If we divide 3170 by 644, we get 4 and a remainder of 594.
Use 4 as the next digit of our solution. 
Result so far: 2153.4
Subtracting 2576 from 3170 leaves us with 594.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5940, and continue the process.

Advancing to step 9:
The number 644 fits into 5940 9 times, leaving a remainder of 144.
Write down 9 as next digit of the result. 
Result so far: 2153.49
If we take 5796 away from 5940, we end up with 144.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1440, and continue the process.

Step 10:
If we divide 1440 by 644, we get 2 and a remainder of 152.
The next digit of our result is 2. 
Result so far: 2153.492
If we subtract 1288 from 1440, we get 152.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1520, and continue the process.

Advancing to step 11:
644 goes into 1520 2 times with a remainder of 232.
The number 2 becomes the next digit in our result. 
Result so far: 2153.4922
Subtracting 1288 from 1520 leaves us with 232.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2320, and continue the process.

The final outcome is 2153.4922, with a leftover of 0.00232.