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Topic: Compasses for Geometry
Replies: 7   Last Post: Sep 3, 2014 6:45 AM

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Roberta M. Eisenberg

Posts: 269
Registered: 10/9/09
Re: Compasses for Geometry
Posted: Jul 17, 2014 2:17 PM
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I have always found that Staedtler?s products are exceptionally well-made and do own several. However, my all-time favorite pair of compasses was called the ?Circle Master Compass?. Originally, I got it from Creative Publications or Dale Seymour Publications.

I checked in my desk just now and found that my most recent one (at least 15 years old) was purchased from Key Curriculum Press (must have been after Creative and Dale Seymour went out of business).

After about 10 minutes of searching online, I finally remembered the correct name and found it at EAI.

There is a cheaper one listed at the bottom called Circle Perfect Compass, but for 46¢ more, I?d stick with the Circle Master because the three disks are metal rather than plastic.

The genius of this tool is that you can replace the pencil with a pen (in various colors) or other things and can make larger circles up to 8? in diameter. You can even attach two together to make bigger circles.

The top of the stylus has a small knob for correct use of the compasses (twirl between thumb and forefinger rather than holding across the pencil and stylus)

When you are done with your work, just slide the pencil and the stylus so that the points are inside the three metal disks and screwed down safely.

At the same time, there are three little holes in the disks which can be aligned when you are parking the stylus and pencil points. They are made the exact size to fit on a ring of a loose leaf binder.

The nut and the screw are made so that they open but do not separate so that there is no danger of dropping, and worse losing, them

Chairperson, UFT Math Teachers Committee

PS Some may wonder at my use of the plural rather than the singular for the name of the tool. It is parallel to ?pair of scissors? or ?scissors? for short. Scissor is not correct for the name of that tool and neither is compass for the name of our geometry tool. A compass is a different tool for finding which way is north. I realize I have been waging a losing battle about this for more than 50 years, but at least in my own classes and workshops, we use compasses or pair of compasses.

On Jul 17, 2014, at 11:18 AM, Robin Schwartz <> wrote:

> Hi
> Can anyone recommend a great compass for Geometry?
> Ideally it would be very sturdy and would not move when a student does a construction.
> Has anyone used this?
> I would prefer not to use the SAFET compass for constructions
> Thanks
> Robin Schwartz
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