The hardware factory produced 400 machine tools in April, and the production in May increased by 1/5 compared with April. How many more units were produced in May than in April?
五金厂四月份生产机床400台，五月份比四月份增产(1/5)．五月份比四月份增产多少台？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">400 * (1/5)</gadget>
<output>80</output>

<result>80</result>