$\displaystyle\text{1 ton = 2,000 pounds}\usepackage{cmbright}\Huge\$

so $\displaystyle\text{2 tons = 4,000 pounds}\usepackage{cmbright}\Huge\$

and $\displaystyle{2},{500}\ \text{ pounds}+{4},{000}\ \text{ pounds}={6},{500}\ \text{ pounds}\usepackage{cmbright}\Huge\$ .