其它
$a$ and $$b$$ are reciprocals， $$\frac{2}{a}\div \frac{b}{12}=$$． 
Overseas Competition->Knowledge Point->Calculation Modules->Comparing, Ordering and Estimating->Comparing and Ordering->Comparing and Ordering Fraction by Comparing Its Reciprocal
$$\frac{2}{a}\div \frac{b}{12}= \frac{2}{a}\times \frac{12}{b}= \frac{24}{ab}=24 $$， 