Weld a cuboid frame whose length, width, and height are 50cm, 30cm, and 20cm respectively, how many meters of steel bars are needed?
焊接一个长、宽、高分别为50cm，30cm，20cm的长方体框架，需要钢筋多少m．
<gadget id="calculator">50 + 30 + 20</gadget>
<output>100</output>

<gadget id="calculator">4 / 100</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">100 * (1/25)</gadget>
<output>4</output>

<result>4</result>