66681939 divided by 649 
The aim is to understand the frequency of 649 in 66681939.

Going ahead to step 1:
When dividing 6 by 649, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 649

On to step 2:
649 goes into 66 0 times with a remainder of 66.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 66, we get 66.
Grab the next digit (6) from the dividend, add it to 66, then carry on: 666 / 649

On to step 3:
If we divide 666 by 649, we get 1 and a remainder of 17.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 649 from 666, we get 17.
Fetch the next digit (8) from the dividend, attach it to 17 and continue: 178 / 649

Moving on to step 4:
649 can be fit into 178 0 times, resulting in a remainder of 178.
Put 0 as the next digit of the answer. 
Result so far: 10.0
If we subtract 0 from 178, we get 178.
Fetch the next digit (1) from the dividend, attach it to 178 and continue: 1781 / 649

On to step 5:
1781 divided by 649 is 2 with a remainder of 483.
Put 2 as the next digit of the answer. 
Result so far: 102.0
Subtracting 1298 from 1781 leaves us with 483.
Grab the next digit (9) from the dividend, add it to 483, then carry on: 4839 / 649

Moving on to step 6:
The number 649 fits into 4839 7 times, leaving a remainder of 296.
Put 7 as the next digit of the answer. 
Result so far: 1027.0
If we take 4543 away from 4839, we end up with 296.
Take the next digit (3) from the dividend and append it to 296, then repeat: 2963 / 649

Advancing to step 7:
When dividing 2963 by 649, we get 4 with a remainder of 367.
Record the quotient 4 as the next digit in the result. 
Result so far: 10274.0
Subtract 2596 from 2963 to get 367.
Grab the next digit (9) from the dividend, add it to 367, then carry on: 3679 / 649

Let's proceed to step 8:
3679 divided by 649 is 5 with a remainder of 434.
Record the quotient 5 as the next digit in the result. 
Result so far: 102745.0
Subtract 3245 from 3679 to get 434.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4340, and continue the process.

Moving on to step 9:
649 goes into 4340 6 times with a remainder of 446.
The next digit of our result is 6. 
Result so far: 102745.6
Subtract 3894 from 4340 to get 446.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4460, and continue the process.

Going ahead to step 10:
649 can be fit into 4460 6 times, resulting in a remainder of 566.
Use 6 as the next digit of our solution. 
Result so far: 102745.66
If we take 3894 away from 4460, we end up with 566.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5660, and continue the process.

The quotient of the division is 102745.66, and the remainder is 0.566.