Math Teachers at Play #45 via Virtual Math Tutor

The Math Teachers at Play Carnival is up at Virtual Math Tutor for your browsing pleasure. Articles range from preschool to high school level in math, and topics include puzzles, worksheets, games, teaching tips, ideas for the math/science lover on your Christmas gift list, and the cutest math monster I’ve seen in ages. Great fun!

Understanding Algebra: How Many Roots?

In algebra 1, we spend a lot of time working with quadratic equations. Among other things, we want to know how many roots (solutions) an equation has and whether the roots are real or imaginary numbers.

One way to visualize this is by asking:

  • “Which values of x will make the equation equal to zero — that is, will make the graph cross the x-axis?”

I wish my algebra teacher had explained it like James Tanton does. It makes so much sense!