To express the whole number 18 as a fraction, we can represent it as:
- 18/1
This shows that 18 is the same as 18 divided by 1.
Now, to determine if this fraction is in its simplest form, we need to check if there are any common factors between the numerator (18) and the denominator (1). Since 1 does not have any other factors besides itself, we can conclude that:
- The greatest common divisor (GCD) of 18 and 1 is 1.
Therefore, we cannot simplify the fraction any further. As a result, the simplest form of 18 as a fraction is:
- 18/1
In conclusion, 18 is expressed as 18/1 in its simplest fractional form.