Xiao Ming buys a pencil case and two pens, and they share 30 yuan. The unit price of the pen is (1/4) of the pencil case. How much is a pen?
小明买一个文具盒和二支钢笔，共用去30元钱，钢笔单价是文具盒的(1/4)．一支钢笔多少元？
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) / 2</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">30 * (1/6)</gadget>
<output>5</output>

<result>5</result>