fraction subtraction easy

what is 5/8 - 2/3?

${\color{red}\large\frac{5}{8}-\frac{2}{3}}$

$\large= \frac{5\times 3-2\times 8}{8\times 3}$  Smallest common multiple is 24

${\color{blue}\large=-\frac{1}{24}}$     !