The sales volume of a supermarket in March was 3.2 million yuan, and the sales volume in April increased by 800,000 yuan compared with March. What percentage of the sales volume in March was that in April?
一个超市三月份的销售额是320万元，四月份比三月份增加了80万元，三月份的销售额是四月份的百分之几？
<gadget id="calculator">320 + 80</gadget>
<output>400</output>

<gadget id="calculator">320 / 400</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>