In a cotton field, 30 tons of cotton are harvested this year, an increase of 5 tons compared with last year. How many percent has the cotton output of this field increased this year compared to last year?
一块棉花地，今年收棉30吨，比去年增产了5吨．这块棉花地棉产量今年比去年增长了百分之几？
<gadget id="calculator">30 - 5</gadget>
<output>25</output>

<gadget id="calculator">5 / 25</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>