We divide 87243315 by 644
The aim is to understand the frequency of 644 in 87243315.

On to step 1:
If we divide 8 by 644, we get 0 and a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 644

Going ahead to step 2:
644 can be fit into 87 0 times, resulting in a remainder of 87.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 87, we get 87.
Include the next digit (2) from the dividend after 87, then repeat: 872 / 644

Let's proceed to step 3:
872 divided by 644 is 1 with a remainder of 228.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 644 away from 872, we end up with 228.
Bring next digit (4) of the dividend behind the 228 and repeat the process: 2284 / 644

On to step 4:
644 goes into 2284 3 times with a remainder of 352.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
Subtracting 1932 from 2284 leaves us with 352.
Bring next digit (3) of the dividend behind the 352 and repeat the process: 3523 / 644

Let's proceed to step 5:
If we divide 3523 by 644, we get 5 and a remainder of 303.
Put 5 as the next digit of the answer. 
Result so far: 135.0
If we take 3220 away from 3523, we end up with 303.
Include the next digit (3) from the dividend after 303, then repeat: 3033 / 644

Step 6:
644 goes into 3033 4 times with a remainder of 457.
Put 4 as the next digit of the answer. 
Result so far: 1354.0
Subtract 2576 from 3033 to get 457.
Take the next digit (1) from the dividend and append it to 457, then repeat: 4571 / 644

Let's proceed to step 7:
644 goes into 4571 7 times with a remainder of 63.
Use 7 as the next digit of our solution. 
Result so far: 13547.0
If we subtract 4508 from 4571, we get 63.
Append the next digit (5) from the dividend to 63 and continue with: 635 / 644

Moving on to step 8:
The number 644 fits into 635 0 times, leaving a remainder of 635.
The number 0 becomes the next digit in our result. 
Result so far: 135470.0
The remainder is 635 after subtracting 0 from 635.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6350, and continue the process.

Let's proceed to step 9:
If we divide 6350 by 644, we get 9 and a remainder of 554.
The number 9 becomes the next digit in our result. 
Result so far: 135470.9
Subtracting 5796 from 6350 leaves us with 554.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5540, and continue the process.

Let's proceed to step 10:
644 can be fit into 5540 8 times, resulting in a remainder of 388.
The number 8 becomes the next digit in our result. 
Result so far: 135470.98
If we subtract 5152 from 5540, we get 388.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3880, and continue the process.

Let's proceed to step 11:
When dividing 3880 by 644, we get 6 with a remainder of 16.
Put 6 as the next digit of the answer. 
Result so far: 135470.986
Deduct 3864 from 3880 and we're left 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.

On to step 12:
If we divide 160 by 644, we get 0 and a remainder of 160.
The next digit of our result is 0. 
Result so far: 135470.986
Subtract 0 from 160 to get 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Advancing to step 13:
644 can be fit into 1600 2 times, resulting in a remainder of 312.
Record the quotient 2 as the next digit in the result. 
Result so far: 135470.98602
Subtracting 1288 from 1600 leaves us with 312.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3120, and continue the process.

Step 14:
644 goes into 3120 4 times with a remainder of 544.
The number 4 becomes the next digit in our result. 
Result so far: 135470.986024
If we take 2576 away from 3120, we end up with 544.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5440, and continue the process.

Step 15:
If we divide 5440 by 644, we get 8 and a remainder of 288.
Use 8 as the next digit of our solution. 
Result so far: 135470.9860248
Subtract 5152 from 5440 to get 288.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2880, and continue the process.

On to step 16:
2880 divided by 644 is 4 with a remainder of 304.
Put 4 as the next digit of the answer. 
Result so far: 135470.98602484
Subtract 2576 from 2880 to get 304.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3040, and continue the process.

After the division, we end up with 135470.98602484 and a remainder of 3.04e-07.