A piece of mooncake is divided into 5 parts on average, and Yaya eats 2 of them, what fraction of the mooncake is left uneaten?
一块月饼，平均分成5份，丫丫吃了其中的2份，还剩这块月饼的几分之几没吃？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<result>3/5 = around 0.6</result>