A and B process a batch of parts. If A processes 120 parts per day and B processes 80 parts per day, it will take 7 days to complete the processing. How many parts are there in total?
甲、乙两人加工一批零件．如果甲每天加工120个，乙每天加工80个，那么需要7天才能加工完，问这批零件一共有多少个？
<gadget id="calculator">120 * 7</gadget>
<output>840</output>

<gadget id="calculator">80 * 7</gadget>
<output>560</output>

<gadget id="calculator">840 + 560</gadget>
<output>1_400</output>

<result>1_400</result>