6.8 is to the right of 5.9 on a number line, so $\displaystyle{6.8}>{5.9}\usepackage{cmbright}\Huge\$ . And $\displaystyle-{2.5}\usepackage{cmbright}\Huge\$ is to the left of $\displaystyle-{1.9}\usepackage{cmbright}\Huge\$ on a number line, so $\displaystyle-{2.5}<-{1.9}\usepackage{cmbright}\Huge\$ .