In 100 kg of pesticide water, there are 20 kg of powder, how much does the powder account for in the water?
100千克的农药水中，药粉有20千克，药粉占水的多少
<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<gadget id="calculator">20 / 80</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>