Little Naughty bought a book in the bookstore, which has 228 pages in total. He started to read from page 51 and saw page 100. How many pages are left in this book?
小淘气在书店买了一本书，共有228页，他先从第51页看起，看到了第100页，这本书还剩多少页没看？
<gadget id="calculator">100 - 51</gadget>
<output>49</output>

<gadget id="calculator">49 + 1</gadget>
<output>50</output>

<gadget id="calculator">228 - 50</gadget>
<output>178</output>

<result>178</result>