A certain pig farm raises 400 pigs this year, which is 25% more than last year. How many more pigs are raised than last year?
某养猪场，今年养猪400头，比去年多养25%，比去年多养多少头？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">400 / (5/4)</gadget>
<output>320</output>

<result>320</result>