A book has 80 pages. Xiao Ming reads it every day (1/10). He has read it for 5 days. How many pages are left?
一本书80页，小明每天看(1/10)，已经看了5天，还剩多少页没看？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 5</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 * (1/2)</gadget>
<output>40</output>

<result>40</result>