There were 78 people doing exercise in the square on Sunday, 46 people came in halfway, and 69 people left at noon. How many people are there in the square now?
星期天广场上有78人在做运动操，中途又来了46人，中午时走了69人．现在广场上还有多少人？
<gadget id="calculator">46 - 69</gadget>
<output>-23</output>

<gadget id="calculator">78 + (-23)</gadget>
<output>55</output>

<result>55</result>