The master and apprentice cooperate to complete the production task of 240 parts. After a few days, the master completed (2/5) of the total number, and the apprentice completed (1/3) of the total number. How many parts are left unfinished?
师徒合作完成240个零件的生产任务，几天后，师傅完成了总数的(2/5)，徒弟完成了总数的(1/3)，还剩下多少个没完成？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (2/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">240 * (4/15)</gadget>
<output>64</output>

<result>64</result>