Thinking Mathematically (6th Edition)

$\dfrac{2}{5}$
Reduce a number to its lowest terms by factoring the numerator and the denominator and then cancelling common factors: $\require{cancel}=\dfrac{2(16)}{5(16)} \\=\dfrac{2\cancel{(16)}}{5\cancel{(16)}} \\=\dfrac{2}{5}$