We look at the division of 81660144 by 263 
The aim is to understand the frequency of 263 in 81660144.

Going ahead to step 1:
If we divide 8 by 263, we get 0 and a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 263

On to step 2:
If we divide 81 by 263, we get 0 and a remainder of 81.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 81 to get 81.
Grab the next digit (6) from the dividend, add it to 81, then carry on: 816 / 263

Let's proceed to step 3:
When dividing 816 by 263, we get 3 with a remainder of 27.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 789 from 816 and we're left with 27.
Include the next digit (6) from the dividend after 27, then repeat: 276 / 263

Moving on to step 4:
When dividing 276 by 263, we get 1 with a remainder of 13.
Use 1 as the next digit of our solution. 
Result so far: 31.0
Deduct 263 from 276 and we're left with 13.
Append the next digit (0) from the dividend to 13 and continue with: 130 / 263

Let's proceed to step 5:
When dividing 130 by 263, we get 0 with a remainder of 130.
Use 0 as the next digit of our solution. 
Result so far: 310.0
The remainder is 130 after subtracting 0 from 130.
Take the next digit (1) from the dividend and append it to 130, then repeat: 1301 / 263

Advancing to step 6:
1301 divided by 263 is 4 with a remainder of 249.
The next digit of our result is 4. 
Result so far: 3104.0
If we take 1052 away from 1301, we end up with 249.
Take the next digit (4) from the dividend and append it to 249, then repeat: 2494 / 263

Step 7:
If we divide 2494 by 263, we get 9 and a remainder of 127.
Write down 9 as next digit of the result. 
Result so far: 31049.0
Deduct 2367 from 2494 and we're left with 127.
Append the next digit (4) from the dividend to 127 and continue with: 1274 / 263

Advancing to step 8:
The number 263 fits into 1274 4 times, leaving a remainder of 222.
Put 4 as the next digit of the answer. 
Result so far: 310494.0
Subtract 1052 from 1274 to get 222.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2220, and continue the process.

Advancing to step 9:
When dividing 2220 by 263, we get 8 with a remainder of 116.
Use 8 as the next digit of our solution. 
Result so far: 310494.8
If we take 2104 away from 2220, we end up with 116.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1160, and continue the process.

Step 10:
If we divide 1160 by 263, we get 4 and a remainder of 108.
Record the quotient 4 as the next digit in the result. 
Result so far: 310494.84
If we take 1052 away from 1160, we end up with 108.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Step 11:
If we divide 1080 by 263, we get 4 and a remainder of 28.
Record the quotient 4 as the next digit in the result. 
Result so far: 310494.844
If we take 1052 away from 1080, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Our division results in 310494.844 with a remaining 0.0028.