How many iron sheets are needed to make a cuboid water tank with a length of 5m, a width of 3m, and a height of 2m.
做长5m，宽3m，高2m长方体的水箱需要多少铁皮．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">15 + 10 + 6</gadget>
<output>31</output>

<gadget id="calculator">31 * 2</gadget>
<output>62</output>

<result>62</result>