The sum of (1/2) and (2/5) of a number is (2/15), what is this number?
一个数的(1/2)与(2/5)的和是(2/15)，这个数是多少？
<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(4/15) / (1/2)</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>