The problem of environmental pollution in China is very prominent, and domestic waste is one of the pollution sources. According to statistics, the average family in the country discards 4 waste plastic bags every day, and the country has a population of 1.3 billion. If the average family counts as 5 people, and the average per 1,000 plastic bags is calculated as 0.5 kg, how many tons of plastic bags are discarded in the country in a day? ?
中国环境污染问题十分突出，生活垃圾是其中的污染源之一．据统计全国平均每个家庭每天丢弃废塑料袋4个，全国13亿人口，如果平均每个家庭按5人计算，平均每1000个塑料袋按0.5公斤计算，全国一天丢弃的塑料袋有多少吨？
<gadget id="calculator">1_300_000_000 / 5</gadget>
<output>260_000_000</output>

<gadget id="calculator">4 / 1_000</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">260_000_000 * (1/250)</gadget>
<output>1_040_000</output>

<gadget id="calculator">0.5 / 1_000</gadget>
<output>0.0005</output>

<gadget id="calculator">1_040_000 * 0.0005</gadget>
<output>520</output>

<result>520</result>