A wheat experimental field produces 30 tons of wheat this year, an increase of 25% compared to last year. How many tons of wheat was produced last year?
一块小麦试验田，今年产小麦30吨，比去年增产二成五，去年产小麦多少吨？
<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">30 / (5/4)</gadget>
<output>24</output>

<result>24</result>