There were 420 TV sets in a certain mountainous area last year, and this year it has increased by 45% compared to last year. How many TV sets are there this year?
某山区去年有电视机420台，今年比去年增加45%，今年有电视机多少台？
<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 + (9/20)</gadget>
<output>29/20 = around 1.45</output>

<gadget id="calculator">420 * (29/20)</gadget>
<output>609</output>

<result>609</result>