A professional cattle breeding household raises 6 dairy cows, each of which is worth 4,000 yuan. According to regulations, the insurance amount of dairy cow insurance can only be calculated at 70% of the value at the time of insurance. If the annual insurance premium rate is 0.3%, how much does this professional household have to pay for the insurance premium every year?
一个养牛专业户养了6头奶牛，每头奶牛价值4000元．根据规定，奶牛保险的保险金额只能按参加保险时价值的七成计算．如果每年的保险费率是0.3%，这个专业户每年要交保险费多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">0.3 / 100</gadget>
<output>0.003</output>

<gadget id="calculator">4_000 * 6 * (7/10) * 0.003</gadget>
<output>50.4</output>

<result>50.4</result>