How many square meters of glass is needed to make a cuboid glass fish tank without a cover whose bottom side is 4 decimeters long and 50 centimeters high?
做一个底面边长是4分米、高50厘米的长方体的无盖玻璃鱼缸，至少需要多少平方米的玻璃？
<gadget id="calculator">0.2 * 4</gadget>
<output>0.8</output>

<gadget id="calculator">0.16 + 0.8</gadget>
<output>0.96</output>

<result>0.96</result>