Xiao Ming's father made a cuboid goldfish tank without a cover, which is 50 cm long, 30 cm wide and 40 cm high. How many square centimeters of glass is needed to make this gold fish tank?
小明的爸爸做了一个无盖的长方体金鱼缸，长50厘米，宽30厘米，高40厘米，做这个金鱼缸至少需要多少平方厘米的玻璃？
<gadget id="calculator">50 * 30</gadget>
<output>1_500</output>

<gadget id="calculator">50 * 40 * 2</gadget>
<output>4_000</output>

<gadget id="calculator">30 * 40 * 2</gadget>
<output>2_400</output>

<gadget id="calculator">1_500 + 4_000 + 2_400</gadget>
<output>7_900</output>

<result>7_900</result>