Xiaohua reads a story book, read (1/10) on the first day, 35 pages on the second day, and read 7 pages, which is exactly 40% of the whole book. How many pages did Xiaohua read on the first day?
小华读一本故事书，第一天读了(1/10)，第二天读了35页，再读7页恰好是全书的40%，小华第一天读了多少页？
<gadget id="calculator">35 + 7</gadget>
<output>42</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/5) - (1/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">42 / (3/10)</gadget>
<output>140</output>

<gadget id="calculator">140 * (1/10)</gadget>
<output>14</output>

<result>14</result>