Mom bought a bag of 30 kilograms of rice. 40% has been eaten, how many kilograms of rice are left uneaten.
妈妈买了一袋30千克的大米．己经吃了40%，还剩多少千克大米没有吃．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 * (3/5)</gadget>
<output>18</output>

<result>18</result>