A number minus (2/5), plus (1/4) equals (5/8), find this number.
一个数减去(2/5)，再加上(1/4)等于(5/8)，求这个数．
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(5/8) - (1/4)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/8) + (2/5)</gadget>
<output>31/40 = around 0.775</output>

<result>31/40 = around 0.775</result>