History of Numbers

This page at Math is Fun about the history of numbers--including zero, and negative numbers--is quite interesting and will be helpful for you for learning adding and subtracting of positive and negative number (aka integers). As you will see, the invention of zero and negative numbers have allowed such things as debt and, eventually, bankruptcy. As a result, Mr Peel could "buy" the boat pictured below, even though he, in no way, can actually afford it.