You may have used the multiplication expression $\displaystyle{4}\frac{{3}}{{4}}\cdot\frac{{1}}{{16}}\usepackage{cmbright}\Huge\$ . You need to use division to solve the problem: $\displaystyle{4}\frac{{3}}{{4}}\div\frac{{1}}{{16}}\usepackage{cmbright}\Huge\$