There are 20 stickers on a page. If you have 12 pages of stickers but lose one of the pages, then how many stickers would you have? Let's be accurate as possible.
After losing one of the pages you have 12 - 1 = 11 pages of stickers. If each page has 20 stickers on it, you have 11 x 20 = 220 stickers.
The answer: 220.