$\displaystyle{4}\frac{{1}}{{3}}={3}+{1}+\frac{{1}}{{3}}={3}+\frac{{3}}{{3}}+\frac{{1}}{{3}}={3}\frac{{4}}{{3}}\usepackage{cmbright}\Huge\$ . Then subtract: $\displaystyle{3}\frac{{4}}{{3}}-{1}\frac{{2}}{{3}}={2}\frac{{2}}{{3}}\usepackage{cmbright}\Huge\$ .