9889780 ÷ 661 
The aim is to understand the frequency of 661 in 9889780.

Step 1:
9 divided by 661 is 0 with a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Grab the next digit (8) from the dividend, add it to 9, then carry on: 98 / 661

Advancing to step 2:
The number 661 fits into 98 0 times, leaving a remainder of 98.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 98 after subtracting 0 from 98.
Take the next digit (8) from the dividend and append it to 98, then repeat: 988 / 661

Advancing to step 3:
If we divide 988 by 661, we get 1 and a remainder of 327.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 661 from 988 leaves us with 327.
Take the next digit (9) from the dividend and append it to 327, then repeat: 3279 / 661

Step 4:
When dividing 3279 by 661, we get 4 with a remainder of 635.
Write down 4 as next digit of the result. 
Result so far: 14.0
The remainder is 635 after subtracting 2644 from 3279.
Bring next digit (7) of the dividend behind the 635 and repeat the process: 6357 / 661

Going ahead to step 5:
661 can be fit into 6357 9 times, resulting in a remainder of 408.
Put 9 as the next digit of the answer. 
Result so far: 149.0
The remainder is 408 after subtracting 5949 from 6357.
Bring next digit (8) of the dividend behind the 408 and repeat the process: 4088 / 661

Going ahead to step 6:
4088 divided by 661 is 6 with a remainder of 122.
Record the quotient 6 as the next digit in the result. 
Result so far: 1496.0
Subtract 3966 from 4088 to get 122.
Take the next digit (0) from the dividend and append it to 122, then repeat: 1220 / 661

Moving on to step 7:
When dividing 1220 by 661, we get 1 with a remainder of 559.
Record the quotient 1 as the next digit in the result. 
Result so far: 14961.0
If we take 661 away from 1220, we end up with 559.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5590, and continue the process.

Going ahead to step 8:
661 can be fit into 5590 8 times, resulting in a remainder of 302.
The next digit of our result is 8. 
Result so far: 14961.8
If we take 5288 away from 5590, we end up with 302.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3020, and continue the process.

Going ahead to step 9:
If we divide 3020 by 661, we get 4 and a remainder of 376.
Record the quotient 4 as the next digit in the result. 
Result so far: 14961.84
If we subtract 2644 from 3020, we get 376.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3760, and continue the process.

On to step 10:
When dividing 3760 by 661, we get 5 with a remainder of 455.
Put 5 as the next digit of the answer. 
Result so far: 14961.845
Subtracting 3305 from 3760 leaves us with 455.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4550, and continue the process.

Advancing to step 11:
661 can be fit into 4550 6 times, resulting in a remainder of 584.
The next digit of our result is 6. 
Result so far: 14961.8456
The remainder is 584 after subtracting 3966 from 4550.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5840, and continue the process.

Step 12:
The number 661 fits into 5840 8 times, leaving a remainder of 552.
Use 8 as the next digit of our solution. 
Result so far: 14961.84568
Subtracting 5288 from 5840 leaves us with 552.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5520, and continue the process.

Let's proceed to step 13:
661 goes into 5520 8 times with a remainder of 232.
The next digit of our result is 8. 
Result so far: 14961.845688
The remainder is 232 after subtracting 5288 from 5520.
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 result is 14961.845688 with a remainder of 2.32e-05.