We look at the division of 81341205 by 561 
The aim is to understand the frequency of 561 in 81341205.

Let's proceed to step 1:
The number 561 fits into 8 0 times, leaving a remainder of 8.
Record the quotient 0 as the next digit in 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 / 561

Let's proceed to step 2:
81 divided by 561 is 0 with a remainder of 81.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 81 after subtracting 0 from 81.
Take the next digit (3) from the dividend and append it to 81, then repeat: 813 / 561

Going ahead to step 3:
If we divide 813 by 561, we get 1 and a remainder of 252.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 561 away from 813, we end up with 252.
Append the next digit (4) from the dividend to 252 and continue with: 2524 / 561

Step 4:
2524 divided by 561 is 4 with a remainder of 280.
The next digit of our result is 4. 
Result so far: 14.0
Deduct 2244 from 2524 and we're left with 280.
Fetch the next digit (1) from the dividend, attach it to 280 and continue: 2801 / 561

Step 5:
When dividing 2801 by 561, we get 4 with a remainder of 557.
The number 4 becomes the next digit in our result. 
Result so far: 144.0
The remainder is 557 after subtracting 2244 from 2801.
Take the next digit (2) from the dividend and append it to 557, then repeat: 5572 / 561

Step 6:
When dividing 5572 by 561, we get 9 with a remainder of 523.
The next digit of our result is 9. 
Result so far: 1449.0
Deduct 5049 from 5572 and we're left with 523.
Grab the next digit (0) from the dividend, add it to 523, then carry on: 5230 / 561

On to step 7:
The number 561 fits into 5230 9 times, leaving a remainder of 181.
The next digit of our result is 9. 
Result so far: 14499.0
If we subtract 5049 from 5230, we get 181.
Bring next digit (5) of the dividend behind the 181 and repeat the process: 1815 / 561

Going ahead to step 8:
When dividing 1815 by 561, we get 3 with a remainder of 132.
Put 3 as the next digit of the answer. 
Result so far: 144993.0
If we take 1683 away from 1815, we end up with 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

On to step 9:
If we divide 1320 by 561, we get 2 and a remainder of 198.
The next digit of our result is 2. 
Result so far: 144993.2
If we subtract 1122 from 1320, we get 198.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1980, and continue the process.

On to step 10:
1980 divided by 561 is 3 with a remainder of 297.
Use 3 as the next digit of our solution. 
Result so far: 144993.23
If we take 1683 away from 1980, we end up with 297.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2970, and continue the process.

Let's proceed to step 11:
561 goes into 2970 5 times with a remainder of 165.
The number 5 becomes the next digit in our result. 
Result so far: 144993.235
If we subtract 2805 from 2970, we get 165.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1650, and continue the process.

Going ahead to step 12:
If we divide 1650 by 561, we get 2 and a remainder of 528.
The number 2 becomes the next digit in our result. 
Result so far: 144993.2352
The remainder is 528 after subtracting 1122 from 1650.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5280, and continue the process.

Let's proceed to step 13:
561 goes into 5280 9 times with a remainder of 231.
Put 9 as the next digit of the answer. 
Result so far: 144993.23529
Subtracting 5049 from 5280 leaves us with 231.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2310, and continue the process.

Step 14:
561 can be fit into 2310 4 times, resulting in a remainder of 66.
The next digit of our result is 4. 
Result so far: 144993.235294
Subtract 2244 from 2310 to get 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Going ahead to step 15:
561 can be fit into 660 1 times, resulting in a remainder of 99.
Write down 1 as next digit of the result. 
Result so far: 144993.2352941
Subtract 561 from 660 to get 99.
Since there are no more digits in the dividend, we add a zero to the remainder making it 990, and continue the process.

Going ahead to step 16:
The number 561 fits into 990 1 times, leaving a remainder of 429.
The number 1 becomes the next digit in our result. 
Result so far: 144993.23529411
Deduct 561 from 990 and we're left with 429.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4290, and continue the process.

After the division, we end up with 144993.23529411 and a remainder of 4.29e-07.