Add (2/5) to (5/6) of a number, and the sum is (3/5). What is this number?
一个数的(5/6)加上(2/5)，和是(3/5)．这个数是多少？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(1/5) / (5/6)</gadget>
<output>6/25 = around 0.24</output>

<result>6/25 = around 0.24</result>