You can actually switch the calculator to a "fractions calculator," and then type the fractions in there. This post might help you out: http://web2.0calc.com/questions/how-do-i-type-in-fractions
$${\frac{{\mathtt{y}}}{{\mathtt{2}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{6}} = -{\mathtt{7}}$$
.You can actually switch the calculator to a "fractions calculator," and then type the fractions in there. This post might help you out: http://web2.0calc.com/questions/how-do-i-type-in-fractions