Xiao Ming spends 18 yuan, buys two books and spends (1/6) of which is 1 yuan more. How much is each book on average?
小明用18元钱，买两本书用去其中的(1/6)还多1元，平均每本书是多少元
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">18 * (1/6)</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

<result>2</result>