Xiaogang paints 40% of a piece of rectangular paper with blue, and paints the remaining part (3/5) with red. The part painted in red is the amount of this paper.
小刚将一张长方形纸的40%涂上蓝色，将剩下部分的(3/5)涂上红色，涂上红色的部分是这张纸的多少．
<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">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) * (3/5)</gadget>
<output>9/25 = around 0.36</output>

<result>9/25 = around 0.36</result>