piece of colored paper, (2/7) was used for the first origami crane, and (3/7) was used for the second time to make a small flower. How much? How much of this paper is left?
一张彩色纸，第一次折纸鹤用去了这张纸的(2/7)，第二次做小花又用去了(3/7)，两次一共用去了这张纸的几分之几？还剩下这张纸的几分之几？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<result>2/7 = around 0.285714</result>