There were 452 tourists in the science and technology park in the morning, 152 people left at noon, and 449 tourists came in the afternoon. How many tourists are there in the park?
科技园上午游客452人，中午有152人离去，下午又来了449位游客，园内还有多少位游客．
<gadget id="calculator">452 - 152</gadget>
<output>300</output>

<gadget id="calculator">300 + 449</gadget>
<output>749</output>

<result>749</result>