Xiaohua reads a storybook, read 15% of the whole book on the first day, 48 pages on the second day, and left 45% of the book, how many pages did Xiaohua read on the first day?
小华看一本故事书，第一天看了全书的15%，第二天看了48页，还剩全书的45%没有看，小华第一天看了多少页？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (3/20) - (9/20)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">48 / (2/5)</gadget>
<output>120</output>

<gadget id="calculator">120 * (3/20)</gadget>
<output>18</output>

<result>18</result>