if the numerators are the same, the smaller the denominator is, the larger the denominator is. for example 1/2>1/3;

if the denominators are the same, the numerator is larger. for example, 2/3>1/3;

if the numerator and denominator are different, first divide them (mesh) and then compare the sizes. for example, 1/3 (=4/12)>1/4 (=3/12)