$\displaystyle{1}\frac{{2}}{{7}}=\frac{{9}}{{7}}\usepackage{cmbright}\Huge\$ , so it is a rational number. Since $\displaystyle{1}\frac{{2}}{{7}}\usepackage{cmbright}\Huge\$ is between 1 and 2 on the number line, it cannot be an integer, whole number, or natural number.