Sharing ideas for teaching math in the middle school.
Thursday, December 10, 2009
The Real Number System
To help students remember how to identify numbers in the real number system my teaching partner and I came up with the saying, "Now What Is Real?". The "N" stands for natural, or counting numbers; 1,2,3,...No zero. "W" represents whole numbers; 0,1,2,3,...With zero. "I" stands for integers;...-1,0,1,...numbers found In the number line. "R" represents rational numbers, any number that can be written as a fraction. Rational is "fractional". We also explain how fractions can be written as decimals. Numbers that do not fall into any of the above categories are Irrational numbers such as Pi.
The above letters are placed in a triangle with the Natural Numbers at the top going in order with the Rational Numbers on the bottom. This visual tool shows for example that all natural numbers are rational, but not all rational numbers are natural.