75911866 ÷ 3 
The aim is to understand the frequency of 3 in 75911866.

Step 1:
7 divided by 3 is 2 with a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Deduct 6 from 7 and we're left with 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 3

Step 2:
3 can be fit into 15 5 times, resulting in a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 25.0
Subtract 15 from 15 to get 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 3

On to step 3:
When dividing 9 by 3, we get 3 with a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 253.0
If we subtract 9 from 9, we get 0.
Take the next digit (1) from the dividend and append it to 0, then repeat: 1 / 3

Going ahead to step 4:
When dividing 1 by 3, we get 0 with a remainder of 1.
The next digit of our result is 0. 
Result so far: 2530.0
If we subtract 0 from 1, we get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 3

Step 5:
When dividing 11 by 3, we get 3 with a remainder of 2.
Write down 3 as next digit of the result. 
Result so far: 25303.0
If we subtract 9 from 11, we get 2.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 3

On to step 6:
If we divide 28 by 3, we get 9 and a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 253039.0
If we subtract 27 from 28, we get 1.
Append the next digit (6) from the dividend to 1 and continue with: 16 / 3

Step 7:
3 can be fit into 16 5 times, resulting in a remainder of 1.
The number 5 becomes the next digit in our result. 
Result so far: 2530395.0
Subtract 15 from 16 to get 1.
Append the next digit (6) from the dividend to 1 and continue with: 16 / 3

Let's proceed to step 8:
3 goes into 16 5 times with a remainder of 1.
Write down 5 as next digit of the result. 
Result so far: 25303955.0
If we take 15 away from 16, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 9:
3 goes into 10 3 times with a remainder of 1.
Record the quotient 3 as the next digit in the result. 
Result so far: 25303955.3
Subtract 9 from 10 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 10:
3 goes into 10 3 times with a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 25303955.33
Subtract 9 from 10 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

After the division, we end up with 25303955.33 and a remainder of 0.001.