Xiaoqiang read a 320-page story book. He read several pages on the first day, and 64 pages on the second day. He read 60% of the book in two days. How much of the book did he read on the first day?
小强看了一本320页的故事书，第一天看了若干页，第二天看了64页，两天共看了这本书的60%，第一天看了这本书的多少．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">320 * (3/5)</gadget>
<output>192</output>

<gadget id="calculator">192 - 64</gadget>
<output>128</output>

<gadget id="calculator">128 / 320</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>