Xiao Ming is 139 cm tall, Qing Qing is 141 cm tall, Liu Hong is 148 cm tall, and Xiao Si is 140 cm tall. What is their average height?
小明身高139厘米，青青身高141厘米，刘红身高148厘米，小思身高140厘米算一算他们的平均身高是多少？
<gadget id="calculator">139 + 141 + 148 + 140</gadget>
<output>568</output>

<gadget id="calculator">568 / 4</gadget>
<output>142</output>

<result>142</result>