$\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\$ . However, positive numbers are always to the right of negative numbers on a number line, so $\displaystyle{3.5}>-{7.1}\usepackage{cmbright}\Huge\$ .