There are 15 thousand paper cranes, take out (2/3) and (1/5) of these paper cranes respectively. How much of these paper cranes can you still take out?
有15只千纸鹤，分别拿出这些纸鹤的(2/3)和(1/5)．你还能拿出这些纸鹤的几分之几？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/3) + (1/5)</gadget>
<output>13/15 = around 0.866667</output>

<gadget id="calculator">1 - (13/15)</gadget>
<output>2/15 = around 0.133333</output>

<result>2/15 = around 0.133333</result>