Xiao Ming bought 9 pencils for 4 yuan, and got 40 cents back. How much is each pencil?
小名用4元钱买了9支铅笔，找回了4角钱，每支铅笔多少钱？
<gadget id="calculator">4 - 0.4</gadget>
<output>3.6</output>

<gadget id="calculator">3.6 / 9</gadget>
<output>0.4</output>

<result>0.4</result>