book has 300 pages. Xiao Ming reads 15% of the book every day. He has read it for 6 days. How many pages are left?
一本书300页，小明每天看这本书的15%，他看了6天，还剩多少页没看？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 6</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">300 * (1/10)</gadget>
<output>30</output>

<result>30</result>