Let's use the variable x to represent the numerator of the second fraction. So we have the following equation:
[tex]\frac{1}{2}=\frac{x}{8}[/tex]Solving this equation for x, we have:
[tex]\begin{gathered} \frac{1}{2}=\frac{x}{8} \\ 2x=8 \\ x=\frac{8}{2} \\ x=4 \end{gathered}[/tex]So the numerator for the equivalent fraction is 4.