we can see that 5 divided by 1/3 can be pictured as a rectagule divided is 3 parts (red lines). This rectagle was previously divided in 5 parts (black lines). Hence,
[tex]\begin{gathered} 5\text{ divided by }\frac{1}{3}\text{ is equal to 15 parts. In other words} \\ \frac{5}{\frac{1}{3}}=\frac{\frac{5}{1}}{\frac{1}{3}}=\frac{5\cdot3}{1\cdot1}=\frac{15}{1}=15 \end{gathered}[/tex]
In which we used the "sandwich law"
