A museum has 328 visitors in the morning, 189 people leave at noon, and 217 people come in the afternoon. How many people were visiting the museum at this time?
某博物馆上午有328人参观，中午有189人离去，下午又来了217人．这时在博物馆内参观的有多少人？
<gadget id="calculator">328 - 189</gadget>
<output>139</output>

<gadget id="calculator">139 + 217</gadget>
<output>356</output>

<result>356</result>