We look at the division of 11887781 by 646 
The aim is to understand the frequency of 646 in 11887781.

Going ahead to step 1:
1 divided by 646 is 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Grab the next digit (1) from the dividend, add it to 1, then carry on: 11 / 646

On to step 2:
If we divide 11 by 646, we get 0 and a remainder of 11.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 11, we get 11.
Grab the next digit (8) from the dividend, add it to 11, then carry on: 118 / 646

Let's proceed to step 3:
When dividing 118 by 646, we get 0 with a remainder of 118.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 118, we end up with 118.
Include the next digit (8) from the dividend after 118, then repeat: 1188 / 646

Step 4:
The number 646 fits into 1188 1 times, leaving a remainder of 542.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 646 from 1188 leaves us with 542.
Take the next digit (7) from the dividend and append it to 542, then repeat: 5427 / 646

Moving on to step 5:
646 goes into 5427 8 times with a remainder of 259.
The number 8 becomes the next digit in our result. 
Result so far: 18.0
If we subtract 5168 from 5427, we get 259.
Include the next digit (7) from the dividend after 259, then repeat: 2597 / 646

On to step 6:
2597 divided by 646 is 4 with a remainder of 13.
The next digit of our result is 4. 
Result so far: 184.0
If we subtract 2584 from 2597, we get 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 646

Step 7:
138 divided by 646 is 0 with a remainder of 138.
Use 0 as the next digit of our solution. 
Result so far: 1840.0
If we take 0 away from 138, we end up with 138.
Bring next digit (1) of the dividend behind the 138 and repeat the process: 1381 / 646

Let's proceed to step 8:
1381 divided by 646 is 2 with a remainder of 89.
Put 2 as the next digit of the answer. 
Result so far: 18402.0
If we take 1292 away from 1381, we end up with 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Advancing to step 9:
When dividing 890 by 646, we get 1 with a remainder of 244.
Put 1 as the next digit of the answer. 
Result so far: 18402.1
Subtract 646 from 890 to get 244.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2440, and continue the process.

On to step 10:
When dividing 2440 by 646, we get 3 with a remainder of 502.
Use 3 as the next digit of our solution. 
Result so far: 18402.13
Subtracting 1938 from 2440 leaves us with 502.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5020, and continue the process.

Going ahead to step 11:
The number 646 fits into 5020 7 times, leaving a remainder of 498.
Record the quotient 7 as the next digit in the result. 
Result so far: 18402.137
Subtracting 4522 from 5020 leaves us with 498.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Let's proceed to step 12:
If we divide 4980 by 646, we get 7 and a remainder of 458.
Write down 7 as next digit of the result. 
Result so far: 18402.1377
Subtracting 4522 from 4980 leaves us with 458.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4580, and continue the process.

After the division, we end up with 18402.1377 and a remainder of 0.00458.