I am a math teacher, and want to buy something that was owned by one
of my math teachers in high school years ago -- but I cannot manage to
find it online (perhaps I am searching with the wrong terms).

This particular item attaches to the top of a wall-mounted blackboard,
the type you see in a classroom.  I believe it is attached in such a
way that you can slide it left and right.  In its usual state, it
looks more or less like a retracted projector screen, handle and all. 
If you pull the handle, a flat piece of vinyl(?), with roughly the
same proportions as a projector screen (though I think it was green),
is revealed.  Cut into the "screen" is an arrangement of hundreds of
small (1/4", say) circles formed into lines, each "line" parallel or
perpendicular to every other, in a grid.

To use the device, you pull the screen down, "erase" it with a chalky
eraser, and retract it.  The eraser leaves dots in a grid on the
blackboard, creating "graph paper" on the board.  This makes graphing
on the blackboard much easier than the traditional, inaccurate x- and
y-axes with tick marks.

Can anyone find this item online, preferably someplace I can buy it?

rjyanco-ga:

What a truly amazing device! Why didn't they have these in the schools I went to?

I found the roll-up device you are looking for. The sliding mount you
mentioned can be done by pretty much any handy-person using an
industrial track and wheels, using supplies from a local hardware
store, once they have this device in hand in order to measure the
mounting requirements.


Perforated Graph Chart #TB20822T - eNASCO
http://www.enasco.com/prod/ProductDetail?sku=TB20822T

This device is sold by eNASCO.com, the online store for NASCO, a
leading supplier of classroom and teaching tools based in Fort
Atkinson, Wisconsin, USA (they also have a presence in Modesto,
California). Their online catalog is like a toy store for educators.
At the time of my research, this device retails for $58.95.

To think of all the crooked, out-of-scale graphs I had to put up with
as a student...

Please let me know if you require any clarification to this Answer,
and I hope you find this information useful!

----------------------------------
Search Strategy

classroom equipment supply
(led me to the Yahoo! Directory for Education > Supplies and Equipment
where NASCO was the most popular link... I then searched the NASCO
catalog using the word "chalkboard", and went through the nine pages
of hits, finding this on the eighth page)

----------------------------------



Regards,

aht-ga
Google Answers Researcher

Super answer, and very fast.  I don't know how you knew to look at
eNASCO.com, but thank you!

Hi, I looked, but all I could find were these permanently "gridded"
white dry-erase boards
http://www.usmarkerboard.com/page78.html

Your device sounds like a good idea!

Good job aht-ga! I searched many classroom supplies, obviously with no luck!

aht,

I gotta admit, I'm impressed.  And any way you looked at it, it was fast...

~~C

Aht is SO good, it's frightening.

Does G****e really need 500 researchers when it's got one AHT?

How does one pronounce aht anyway?

(I say 'hat' without the 'h')

cool and nice way to find the dam thing