Zhang Ling reads a 120-page story book, read it on the first day (3/10), and read it on the second day (1/5). How many pages did she read less on the second day than on the first day?
张玲看一本120页的故事书，第一天看了(3/10)，第二天看了(1/5)，第二天比第一天少看多少页？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/10) - (1/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">120 * (1/10)</gadget>
<output>12</output>

<result>12</result>