You are about to discover why
A = πr²

The page on the other side of this only has four videos on it. But just two of them individually are worth the price of a password. No kidding. This derivation of πr² is rarely taught to students, or even to teachers. Most of the time when I show this to teachers they have never seen it. I have never shown this to a student who had already seen it in 25 years of doing this.

Not once.

I need to make a more step by step video showing all the different things you need to do to get to this point but for now these short vids will have to do.

The few minutes you spend here may well clear up a lot of confusion and give you a few "a-ha" moments.  If you are a teacher these vids should give you a few ideas. I have taught this to 3rd graders without much difficulty, but as the video says it will take you hours of preparation to get here.

Here is a Pre-view:


Note: from time to time the passwords change. Simply e-mail me for a new one or a new passport as the case may be. Annual passes are good for one year, lifetime passes are good for as long as the site remains up, (site has been up for eight years now).  All single page passwords have lifetime renewal.

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NEW! Series A Manuals Online.  Plus a plethora of PDFs.  

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Get a PASSPORT! The "SITEWIDE" Password gets you in almost everywhere BUT the parent teacher training and 3 other pages. PASSWORD INFO ← Click to find out.

Already have one but it doesn't work anymore? Hit the Contacts tab and email me at gmail for the new one.

Sitewide Password Has Changed as of 14FEB2017.
Training Password Has Changed as of 14FEB2017.
EZPZ & Trig to 8 year olds passwords have changed as of 14FEB2017.

Lifetime Passwords on sale here.

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Most bang for your buck is a Sitewide or AP2 (Sitewide plus Teacher Training Anual Pass 2 Passwords).
Remember these are only good for 1 year.