Each box of tissues was 2.85 yuan, Aunt Xu paid 50 yuan to the salesperson, and got back 4.4 yuan. How many boxes of tissues did she buy?
每盒纸巾2.85元，小徐阿姨付给售货员50元，找回4.4元．她买了几盒纸巾？
<gadget id="calculator">50 - 4.4</gadget>
<output>45.6</output>

<gadget id="calculator">45.6 / 2.85</gadget>
<output>16</output>

<result>16</result>