The number of beef cattle raised in Guangming Farm is 280 fewer than that of dairy cows, and the number of beef cattle is 80% of that of dairy cows. How many beef cattle are there?
光明畜牧场养的肉牛比奶牛少280头，肉牛头数是奶牛的80%．肉牛有多少头？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">280 / (1/5)</gadget>
<output>1_400</output>

<result>1_400</result>