what is 5 over 8 + 1 over 4?
1/4 = 2/8
so
$${\frac{{\mathtt{5}}}{{\mathtt{8}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{2}}}{{\mathtt{8}}}} = {\frac{{\mathtt{7}}}{{\mathtt{8}}}}$$