The area of a piece of paper is (4/5) square meters, what is the area of (1/2) a piece of paper in square meters.
一张纸的面积是(4/5)平方米，(1/2)张纸的面积是多少平方米．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(4/5) * (1/2)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>