The kindergarten bought 100 kilograms of apples and ate (1/5), how many kilograms are left?
幼儿园买来100千克苹果，吃了(1/5)，还剩多少千克？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">100 * (1/5)</gadget>
<output>20</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<result>80</result>