Using 4 identical cups, the heights of the water surface are 8 cm, 5 cm, 4 cm and 3 cm respectively. What is the average height of the four cups of water in centimeters?
用4个同样的杯子，水面的高度分别是8厘米、5厘米、4厘米和3厘米．这四杯水面的平均高度是多少厘米？
<gadget id="calculator">8 + 5 + 4 + 3</gadget>
<output>20</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>