(1/10) of a piece of rectangular paper is painted red, and (3/10) is painted blue. What fraction of the paper is uncolored?
一张长方形纸的(1/10)涂红色，(3/10)涂蓝色．没涂色的部分占这张纸的几分之几？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(1/10) + (3/10)</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>