You may have incorrectly crossed out the 6s and gotten $\displaystyle\frac{{5}}{{4}}\usepackage{cmbright}\Huge\$ . This is not the same as dividing by a common factor. $\displaystyle\frac{{5}}{{4}}\usepackage{cmbright}\Huge\$ is not equivalent to $\displaystyle\frac{{56}}{{64}}\usepackage{cmbright}\Huge\$ .