60991906 ÷ 18 
The aim is to understand the frequency of 18 in 60991906.

On to step 1:
When dividing 6 by 18, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Take the next digit (0) from the dividend and append it to 6, then repeat: 60 / 18

Advancing to step 2:
18 goes into 60 3 times with a remainder of 6.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Deduct 54 from 60 and we're left with 6.
Append the next digit (9) from the dividend to 6 and continue with: 69 / 18

Step 3:
The number 18 fits into 69 3 times, leaving a remainder of 15.
Write down 3 as next digit of the result. 
Result so far: 33.0
If we take 54 away from 69, we end up with 15.
Grab the next digit (9) from the dividend, add it to 15, then carry on: 159 / 18

Moving on to step 4:
18 goes into 159 8 times with a remainder of 15.
Write down 8 as next digit of the result. 
Result so far: 338.0
Deduct 144 from 159 and we're left with 15.
Grab the next digit (1) from the dividend, add it to 15, then carry on: 151 / 18

Step 5:
If we divide 151 by 18, we get 8 and a remainder of 7.
Use 8 as the next digit of our solution. 
Result so far: 3388.0
Deduct 144 from 151 and we're left with 7.
Bring next digit (9) of the dividend behind the 7 and repeat the process: 79 / 18

Let's proceed to step 6:
79 divided by 18 is 4 with a remainder of 7.
Use 4 as the next digit of our solution. 
Result so far: 33884.0
The remainder is 7 after subtracting 72 from 79.
Grab the next digit (0) from the dividend, add it to 7, then carry on: 70 / 18

Let's proceed to step 7:
The number 18 fits into 70 3 times, leaving a remainder of 16.
Write down 3 as next digit of the result. 
Result so far: 338843.0
If we subtract 54 from 70, we get 16.
Grab the next digit (6) from the dividend, add it to 16, then carry on: 166 / 18

Step 8:
If we divide 166 by 18, we get 9 and a remainder of 4.
The next digit of our result is 9. 
Result so far: 3388439.0
If we take 162 away from 166, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 9:
When dividing 40 by 18, we get 2 with a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 3388439.2
Subtract 36 from 40 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 10:
18 goes into 40 2 times with a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 3388439.22
Subtract 36 from 40 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Our division results in 3388439.22 with a remaining 0.004.