The symbols 3/8 and 0.375 are two ways to express the same number, the first as a common fraction and the second as a decimal. To convert 3/8 to its decimal representation divide the denominator, 8 into the numerator, 3. Either use long division or your calculator to perform the division.

If you are presented with 0.375 and you want to represent this number as a common fraction write

\[\ 0.375 = \frac{375}{1000}\]

and simplify, that is convert $\large \frac{375}{1000}$ to an equivalent fraction where the numerator and denominator have no common divisors expect 1.

I hope this helps,
Penny