Teacher Wang took 43.2 yuan to buy stationery. He bought 4 pencils and spent a total of 7.2 yuan. How many more pencils can you buy with the rest of the money?
王老师带着43.2元去买文具，买了4支铅笔共花了7.2元，余下的钱还可以买几支这样的铅笔？
<gadget id="calculator">43.2 - 7.2</gadget>
<output>36</output>

<gadget id="calculator">7.2 / 4</gadget>
<output>1.8</output>

<gadget id="calculator">36 / 1.8</gadget>
<output>20</output>

<result>20</result>