Here are some animations I did to help some concepts, particularly in geometry, “come alive”. The bulleted links will take you to the youtube videos. The bracketed links will download the powerpoint slideshow the video was made from. Feel free to download, modify, and/or link the presentations to fit what you and your students are working on. (Of course, giving me credit is always a classy touch.)

**Basic Rigid Motions (Basic Isometries)**

- Composition of Rigid Motions (translation, rotation, and reflection)
*[pptx]* - Angle-Side-Angle Congruence by Basic Rigid Motions
*[pptx]* - Side-Angle-Side Congruence by Basic Rigid Motions
*[pptx]*

**Multiplication **

**Picturing Multiplication** [*pptx*]

- multiples of 3 [
*mp4*] - multiples of 4 [
*mp4*] - multiples of 5 [
*mp4*] - multiples of 6 [
*mp4*] - multiples of 7 [
*mp4*] - multiples of 8 [
*mp4*] - multiples of 9 [
*mp4*]

**Sieve of Eratosthenes **

**(finding primes < 100)**[

*pptx*]

**Pythagorean Theorem**

- Root Spiral of Theodorus
*[pptx]* - Constructing Square Roots on the Number Line
*[pptx]* - Pythagorean Theorem proof from similar right triangles
*[pptx]*

**Show Your Work (solving for x)**

In this video (made from an old PowerPoint) I was trying to get across a crucial habit to my students so we could see what they were doing—maybe review and applaud, maybe troubleshoot to find where things went wrong. I ought to slick it up a bit, I know, but I think it still has some validity.