\(\frac{1}{2}=\frac{1\times5}{2\times5}=\frac{5}{10}\)
\(\frac{49}{140}=\frac{49:7}{140:7}=\frac{7}{20}=\frac{7\times5}{20\times5}=\frac{35}{100}\)
\(\frac{36}{600}=\frac{36:6}{600:6}=\frac{6}{100}\)
\(\frac{12}{24}=\frac{12\times5}{24\times5}=\frac{60}{100}\)