Dig a cuboid bunker with a length of 5 meters, a width of 2 meters, and a depth of 0.5 meters, and pour 4 cubic meters of fine sand. How thick can it be on average? (solution by equation)
挖一个长方体的沙坑，长5米，宽2米，深0.5米，倒入4立方米细沙，平均能垫多厚？(用方程解)
<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>