On New Year's Day, 402 people came to the zoo in the morning, 109 people left at noon, and 231 people came in the afternoon. How many people are there in the zoo now?
元旦，动物园上午来了402人，中午有109人离去，下午又来了231人，现在动物园有多少人？
<gadget id="calculator">402 - 109</gadget>
<output>293</output>

<gadget id="calculator">293 + 231</gadget>
<output>524</output>

<result>524</result>