The master and the apprentice process a machine part at the same time. The master processes 42 pieces per hour, and the apprentice processes 25 pieces per hour. After 4 o'clock, how many parts were processed by the master and the apprentice?
师傅和徒弟同时加工一种机器零件．师傅每时加工42个，徒弟每时加工25个．4时后，师傅和徒弟一共加工多少个零件？
<gadget id="calculator">42 + 25</gadget>
<output>67</output>

<gadget id="calculator">67 * 4</gadget>
<output>268</output>

<result>268</result>