The master and apprentice process a batch of parts. The master made 80 pieces, which is 10 less than twice the number made by the apprentice. How many did the apprentice do?
师傅和徒弟加工一批零件．师傅做了80个，比徒弟做的个数的2倍少10个．徒弟做了多少个？
<gadget id="calculator">80 + 10</gadget>
<output>90</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<result>45</result>