Let's divide 81561351 by 980
The aim is to understand the frequency of 980 in 81561351.

Step 1:
8 divided by 980 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 980

Step 2:
980 goes into 81 0 times with a remainder of 81.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 81, we end up with 81.
Include the next digit (5) from the dividend after 81, then repeat: 815 / 980

Going ahead to step 3:
The number 980 fits into 815 0 times, leaving a remainder of 815.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 815, we end up with 815.
Append the next digit (6) from the dividend to 815 and continue with: 8156 / 980

On to step 4:
The number 980 fits into 8156 8 times, leaving a remainder of 316.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
Deduct 7840 from 8156 and we're left with 316.
Bring next digit (1) of the dividend behind the 316 and repeat the process: 3161 / 980

On to step 5:
980 can be fit into 3161 3 times, resulting in a remainder of 221.
Put 3 as the next digit of the answer. 
Result so far: 83.0
Deduct 2940 from 3161 and we're left with 221.
Grab the next digit (3) from the dividend, add it to 221, then carry on: 2213 / 980

Moving on to step 6:
980 can be fit into 2213 2 times, resulting in a remainder of 253.
Record the quotient 2 as the next digit in the result. 
Result so far: 832.0
Subtracting 1960 from 2213 leaves us with 253.
Append the next digit (5) from the dividend to 253 and continue with: 2535 / 980

Advancing to step 7:
When dividing 2535 by 980, we get 2 with a remainder of 575.
Use 2 as the next digit of our solution. 
Result so far: 8322.0
If we subtract 1960 from 2535, we get 575.
Grab the next digit (1) from the dividend, add it to 575, then carry on: 5751 / 980

Step 8:
When dividing 5751 by 980, we get 5 with a remainder of 851.
Use 5 as the next digit of our solution. 
Result so far: 83225.0
If we subtract 4900 from 5751, we get 851.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8510, and continue the process.

Let's proceed to step 9:
If we divide 8510 by 980, we get 8 and a remainder of 670.
Put 8 as the next digit of the answer. 
Result so far: 83225.8
Subtract 7840 from 8510 to get 670.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6700, and continue the process.

Moving on to step 10:
980 can be fit into 6700 6 times, resulting in a remainder of 820.
Write down 6 as next digit of the result. 
Result so far: 83225.86
The remainder is 820 after subtracting 5880 from 6700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8200, and continue the process.

Moving on to step 11:
980 goes into 8200 8 times with a remainder of 360.
The number 8 becomes the next digit in our result. 
Result so far: 83225.868
The remainder is 360 after subtracting 7840 from 8200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

On to step 12:
980 goes into 3600 3 times with a remainder of 660.
The number 3 becomes the next digit in our result. 
Result so far: 83225.8683
If we subtract 2940 from 3600, we get 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6600, and continue the process.

Moving on to step 13:
980 goes into 6600 6 times with a remainder of 720.
The next digit of our result is 6. 
Result so far: 83225.86836
If we subtract 5880 from 6600, we get 720.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7200, and continue the process.

Let's proceed to step 14:
980 goes into 7200 7 times with a remainder of 340.
The next digit of our result is 7. 
Result so far: 83225.868367
The remainder is 340 after subtracting 6860 from 7200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3400, and continue the process.

Advancing to step 15:
If we divide 3400 by 980, we get 3 and a remainder of 460.
Use 3 as the next digit of our solution. 
Result so far: 83225.8683673
If we subtract 2940 from 3400, we get 460.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4600, and continue the process.

Going ahead to step 16:
980 can be fit into 4600 4 times, resulting in a remainder of 680.
Write down 4 as next digit of the result. 
Result so far: 83225.86836734
The remainder is 680 after subtracting 3920 from 4600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6800, and continue the process.

After the division, we end up with 83225.86836734 and a remainder of 6.8e-07.