A machine tool factory produced 450 machine tools in May, an increase of 50 units compared with April. By what percentage was the increase in May compared with April?
某机床厂，五月份生产机床450台，比四月份增产50台，五月份比四月份增产百分之几？
<gadget id="calculator">450 - 50</gadget>
<output>400</output>

<gadget id="calculator">50 / 400</gadget>
<output>1/8 = around 0.125</output>

<result>1/8 = around 0.125</result>