The moon cake factory produced 140 tons of moon cakes last year and 210 tons of moon cakes this year. What is the increase in production this year compared to last year?
月饼厂去年生产月饼140吨，今年生产月饼210吨，今年比去年的增产率为多少．
<gadget id="calculator">210 - 140</gadget>
<output>70</output>

<gadget id="calculator">70 / 140</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/2) * 1</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>