A rectangular mirror is 10 decimeters long and 8 decimeters wide. How many decimeters of aluminum alloy material is needed to make an aluminum alloy frame for it?
一面长方形的镜子，长10分米，宽8分米．给它做一个铝合金的边框，大约需要多少分米的铝合金材料？
<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<result>36</result>