You may have added the numerators $\displaystyle{\left({6}+{3}\right)}\usepackage{cmbright}\Huge\$ and added the denominators $\displaystyle{\left({1}+{8}\right)}\usepackage{cmbright}\Huge\$ to get $\displaystyle\frac{{9}}{{9}}={1}\usepackage{cmbright}\Huge\$ instead of multiplying.