The Real Number Line
In Hour 1, you built on your knowledge of basic arithmetic and learned how to evaluate expressions that include variables. In this hour, you move beyond the numbers you’re so familiar with, widening your circle of algebraic knowledge.
Plotting Positives, Negatives, and Zero
The numbers you use for many computation problems are 0, 1, 2, 3, and so on. In algebra, these are defined as whole numbers, and they continue without an end. There is always at least one more whole number after the one you are thinking of at the time. Picture a simple ruler or measuring tape that has only whole numbers. It might look like this one, showing the whole numbers up to 6:
But in real life, you need negative numbers, too, such as ...