Let's divide 83780879 by 678
The aim is to understand the frequency of 678 in 83780879.

On to step 1:
678 can be fit into 8 0 times, resulting in a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Include the next digit (3) from the dividend after 8, then repeat: 83 / 678

On to step 2:
678 goes into 83 0 times with a remainder of 83.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 83, we end up with 83.
Grab the next digit (7) from the dividend, add it to 83, then carry on: 837 / 678

Advancing to step 3:
The number 678 fits into 837 1 times, leaving a remainder of 159.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 678 from 837, we get 159.
Take the next digit (8) from the dividend and append it to 159, then repeat: 1598 / 678

On to step 4:
678 can be fit into 1598 2 times, resulting in a remainder of 242.
The next digit of our result is 2. 
Result so far: 12.0
If we subtract 1356 from 1598, we get 242.
Append the next digit (0) from the dividend to 242 and continue with: 2420 / 678

Step 5:
678 can be fit into 2420 3 times, resulting in a remainder of 386.
Put 3 as the next digit of the answer. 
Result so far: 123.0
If we subtract 2034 from 2420, we get 386.
Fetch the next digit (8) from the dividend, attach it to 386 and continue: 3868 / 678

Going ahead to step 6:
If we divide 3868 by 678, we get 5 and a remainder of 478.
The number 5 becomes the next digit in our result. 
Result so far: 1235.0
Subtracting 3390 from 3868 leaves us with 478.
Take the next digit (7) from the dividend and append it to 478, then repeat: 4787 / 678

On to step 7:
The number 678 fits into 4787 7 times, leaving a remainder of 41.
The number 7 becomes the next digit in our result. 
Result so far: 12357.0
Subtract 4746 from 4787 to get 41.
Take the next digit (9) from the dividend and append it to 41, then repeat: 419 / 678

Moving on to step 8:
678 can be fit into 419 0 times, resulting in a remainder of 419.
Use 0 as the next digit of our solution. 
Result so far: 123570.0
If we subtract 0 from 419, we get 419.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4190, and continue the process.

Advancing to step 9:
4190 divided by 678 is 6 with a remainder of 122.
Use 6 as the next digit of our solution. 
Result so far: 123570.6
If we subtract 4068 from 4190, we get 122.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1220, and continue the process.

Moving on to step 10:
When dividing 1220 by 678, we get 1 with a remainder of 542.
The number 1 becomes the next digit in our result. 
Result so far: 123570.61
If we take 678 away from 1220, we end up with 542.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5420, and continue the process.

Moving on to step 11:
5420 divided by 678 is 7 with a remainder of 674.
The next digit of our result is 7. 
Result so far: 123570.617
Subtracting 4746 from 5420 leaves us with 674.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6740, and continue the process.

Advancing to step 12:
6740 divided by 678 is 9 with a remainder of 638.
The next digit of our result is 9. 
Result so far: 123570.6179
Deduct 6102 from 6740 and we're left with 638.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6380, and continue the process.

Advancing to step 13:
678 can be fit into 6380 9 times, resulting in a remainder of 278.
The next digit of our result is 9. 
Result so far: 123570.61799
Deduct 6102 from 6380 and we're left with 278.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2780, and continue the process.

The final outcome is 123570.61799, with a leftover of 0.000278.