# Free Open Reference Interactive Geometry Book

Check out this website I found at mathopenref.com

I will definitely be using some of the applets here the next time that I teach geometry as part of a pre-algebra course. In fact, maybe I’ll have the students read through this and play with all of the applets as part of their homework (before) coming to class.

# New Slope Game

I hope you enjoy this game!  I would love to have any feedback if you decide to use it.

Other Slope Resources

Applets
1.  Interactive Slope Applet – Although I ran out of time to actually use this with my own class, this is a wonderful resource that lets students click and drag points such that when the line between the point changes, the calculation of the slope of the line also changes on the screen as well.  Very useful!

2.  Slope-Intercept Equation Applet – This appears to be the exact same applet I introduced to you a few weeks ago in the Geogebra Tutorial video.  It’s a very simple resource that allows students to visualize the slope-intercept equation of a line by using sliders to change the slope and y-intercept.

Worksheets

# Statistics Resources from Across the Web

I’m preparing to teach statistics this summer, so statistics resources are on my radar right now.  Here are some that have been fed to me recently:

1.  Prezi on ‘Beyond Tables’ — Awesome Prezi on ditching the tables and integrating applets such as those over at Surf Stat.

2.  YouTube Video – “Benford’s Law — How Mathematics Can Detect Fraud!”  — I wanted to teach Benford’s Law better the last time I taught statistics, but I didn’t know how.  This will help.

3.  10 Jaw-Droppingly Awesome Infographics on Education — If you didn’t see my spiel on Infographics from the last time I taught statistics, I would definitely plan using this assignment again in the future.  This is just one more example of why — Infographics are just so awesome!

4.  Chi-Square Goodness of Fit Resources — Some highlights of a recent web search I did on the topic.

# Interactive Demonstration Tools

Here are a few highlights of some of the Interactive Demonstration Tools that I have come across in the past few weeks:

1.  All Interactive Whiteboard Resources – Although the applets on this website are designed to be friendly for those classrooms with Smartboards and the like, I see no reason why these applets can't be used in any classroom.  In fact, I plan on use this Angle Measure resource when teaching my classes about angles in the upcoming weeks.  Other great resources on this website include this Translation Plotter, which helps students to visualize translating a shape in the Rectangular Coordinate System.

2.  Interactive Slope Applet – Although I ran out of time to actually use this with my own class, this is a wonderful resource that lets students click and drag points such that when the line between the point changes, the calculation of the slope of the line also changes on the screen as well.  Very useful!

3.  Slope-Intercept Equation Applet – This appears to be the exact same applet I introduced to you a few weeks ago in the Geogebra Tutorial video.  It's a very simple resource that allows students to visualize the slope-intercept equation of a line by using sliders to change the slope and y-intercept.

# GeoGebra and Applets for Calculus

Somethings I have learned just by being a little more observant.  One day last week I was sitting at a different table than usual at school, and it happened to be next to the bulletin board.  At the very top of the bulletin board was a flier that I had never seen before that had a list of two websites, one of them being Math Applets for Calculus at St. Louis University.  Personally, I have never been too big of a fan of applets, but most of these are really great.  There are four types of applets there: JCM Applets, Banchoff Applets, Geometer's Sketchpad Applets, GeoGebra Applets.

However, I was actually more interested in GeoGebra than the actual applets, since I had never heard of it before.  It turns out that GeoGebra is a free tool to create learning and teaching materials.  I played a little bit with the web-based version since I didn't really want to download anything that I wasn't so sure about.  And now I can see that it is a terrific resource that I will be using well into the future.  Of course, although I also like the Wolfram Demonstrations Project, I can't get over the fact that you need the Mathematica Player in order to be able to show the demonstrations in class.  And since I don't have the rights to download it in many of the buildings that I teach in, sometimes it is a fail for me.  GeoGebra is different since I can put the Applets directly onto my own webspace.

As a great introduction to using GeoGebra, I highly recommend checking out the video below, which will give you just a small taste of its power and might.  By the way, the guy in the video says GeoGebra incorrectly every time.  It's GEE-AHH-GEBRA, not GEE-O-GEBRA.  I found this out only because I watched another video from the creator of GeoGebra.  Sorry, just a pet peeve, just like when students pronounce EULER incorrectly.

# Teaching the Unit Circle

This is simply another consequence of my poking around the web, and although I haven’t taught trigonometry since last summer, I would consider using either of these ideas in the future:

1.  Touch Trigonometry – This is an interactive trigonometry graph and circle featuring the six basic trig functions.  I wasn’t a fan at first because I’m colorblind, which made it seem like there was just too much going on, but I can see that it is a useful tool for those who are able to distinguish colors.

2.  Serving Unit-Circle Trigonometry on a Paper Plate – At first I thought this was an awful idea for the college classroom, but then one day last summer one of my students came in with something very similar.  I asked him where he got it, and he said that he made it in high school, and that it was one of the most useful things he’s ever made.  And apparently he’s been carrying it around ever since.  Although I still wonder why he was taking my class if it was so useful, the point is that if the students are engaged, I believe it aids greatly in the learning.  Here is a link to a completed project.  And here is a link to a blank circle.

# Wolfram Demonstrations Project: The Double Cone

This afternoon I taught my College Algebra class about the Conic Sections, and The Double Cone project from the Wolfram Demonstrations Project came to mind.  I figured that it deserves a mention since it's the second time this semester that I have used it in my classes when explaning the conic sections.  It really seems to help the students visualize where the conic sections are coming from and why they are called conic sections.

In fact, a few students this afternoon stayed after class to dicuss what they saw on the screen and we even looked a few other demonstrations, including the one on Superquadratics.  I really appreciated the student's input on what they saw, and a few of them even expressed interest in taking a trigonometry, calculus, or computer programming class.