A company wants to advertise on a wall with a length of 70 decimeters and a width of 50 decimeters. If the advertising cloth costs 8 yuan per square meter, how much does it cost to buy the advertising cloth?
某公司要在一面长70分米、宽50分米的墙上做广告，如果每平方米广告布需要8元，那么买广告布一共需要多少钱？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">70 * (1/2) * 8</gadget>
<output>280</output>

<result>280</result>