Showing posts from October, 2008

Linear equations attack the green globs on Halloween!

In lesson 3.3 you learned about linear functions and graphs. As an extension of that lesson I thought it would be useful to try the Great Green Globs challenge because you will need to use the skills you learned in this lesson. And if you didn't learn them all that well, this will be a great opportunity to learn them a fun way. Now using the Globs program ($20 from is the best way to go, but you can still compete anyway. Try this practice game to find out what you will be doing in the contest. Here are the instructions:
1. Download the score sheet and print it out.
2. Watch my Youtube video clip (3:40) to get an idea of how to play the game.
3. Graph the function* and write down the equation as shown in the figure below.

4. Continue drawing and recording equations until all 13 globs have at least one line going through them.

When finished send your list of equations in an email to I will enter your equations into the Globs program to …

Everything You Ever Wanted to Know about Equations, Lines, Slopes, and Graphs but Were Afraid to Ask

The next lesson in chapter 3 of your math book is on graphs, lines, slopes, and equations. Why would you ever want to learn this you might ask? One very good reason is that in the very near future you will be participating in the Great Green Globs Contest and you will need to know all about coordinate geometry. You will learn by playing the Globs game either on the computer* (which is the best way) or with a printout of the score sheet along with a pencil and ruler.

Green Globs: The Game (a description)
Thirteen randomly scattered “green globs” are displayed on a coordinate grid. The goal is to "explode" all the globs by hitting them with the graphs of equations entered on the keyboard (or paper). The scoring algorithm encourages you to hit as many globs as possible with each equation in order to get the best possible score.

The following lesson will help you to learn all you need to know about graphing equations to succeed in Green Globs. Have a good time, but don’t fo…

Lesson 3.3 Functions with Line Graphs

So far we have seen that functions can take on different forms such as an equation, a table or a graph. In lessons 1 and 2 the “guess my rule” function machine metaphor helped to show the connection between the rule and the table. Lesson 3 graphing functions (more specifically, linear equations) is the focus.

As usual, Mr. Jacobs likes to present a motivational activity to start and he uses in Edition 3 the story about Robert Wadlow who at one time was the tallest man in the world to show the relationship between age and height. There is a marvelous website about Mr. Wadlow at which is a fascinating read.

Note: The word rule is used interchangeably with equation and even sometimes with function. This can cause confusion because a rule doesn’t always have to be an equation and not all equations are necessarily functions depending on how it’s defined. For example a mathematical rule (which is what we are talking about here) could be an ineq…