100 teachers and students go to a picnic, each teacher eats 2 meat buns, 2 students eat 1 meat bun, a total of 80 meat buns, how many teachers?
100名师生去野餐，老师每人吃2个肉包，学生2人吃1个肉包，共吃80个肉包，几名老师？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">100 * (1/2)</gadget>
<output>50</output>

<gadget id="calculator">80 - 50</gadget>
<output>30</output>

<gadget id="calculator">2 - (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">30 / (3/2)</gadget>
<output>20</output>

<result>20</result>