how much is 20% of 200

20/100*200

there is a calc on the home page

or

$$\\\frac{20}{100} \times 200\\\\
=\frac{20}{1\not{0}\not{0}}\;\times \frac{\;2\not{0}\not{0}}{1}\\\\
=\frac{2}{1}\times \frac{2}{1}\\\\
=2\times 2\\\\
=4$$