7th grade student pre-writing about negative numbers

What I Know About Negative Numbers

I know that negative numbers are less than zero. I know it sounds crazy. What number could be less than zero? Well, when I was little, im not sure how little, but it was before 3rd grade, my dad read me a story in a kids magazine about the origin of zero(I know, my dad's like, a total math freak right?) and it said things like what number systems were like without zeros, blah blah blah, and it mentioned negative numbers in passing. I was confused, so dad said "Think of negative numbers as a vacume. Look, if I turned this glass over on the kitchen table (demonstrated with glass) and there was nothing in it, that would be like zero. Now lets say I took a vacume and sucked all the air out. That would be like negative numbers, because they suck up positive numbers." Later on, I noticed a number line in the math room that not only showed positive numbers, but also negative numbers. Looking at the number line, I decided that negative numbers must be the same as positive numbers, only with a negative sign next to them. Therefore, -2 + -2 must be -4, just like 2+2 is 4. Then I read in a book (I think the book was Things Not Seen by Andrew Clements) that any negative number time another negative number equals a positive number. Those are the things I know about negative numbers.