1. The day before yesterday, yesterday, today, tomorrow, the day after tomorrow.
2. Most people read "The cow ate the grass" when they first try this. However, "the" actually appears twice in the sentence, which is easily missed due to the way our brains look for and find familiar patterns - even when they are not there.
3. 1.5 (I didn't say it was a whole number.)
4. Eye (rhymes with "I".)
5. Cut it as you normally cut a cake, in half with one cut, and again with another, resulting in four pieces. Then cut it horizontally in half. This third cut creates eight pieces total.