The income of Xiaoming's family was 45,000 yuan the year before last, and last year's income was 1/5 higher than that of the previous year. How much more did you earn last year than the year before?
小明家前年收入4.5万元，去年收入比前年增加(1/5)．去年比前年多收入多少元？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4.5 * (1/5)</gadget>
<output>0.9</output>

<result>0.9</result>