[Blindmath] Millimeter ruler?

Tue Sep 23 22:41:40 UTC 2014

Hi Everyone,

I would not recommend the braille ruler from MaxiAids identified below.
First of all, it is not a metric ruler. The precision is in inches. The
greatest precision in print is 1/16 inch, but the precision tactually is
only 1/8 inch. This is quite the cluttered ruler. They could not fit in
raised markings for a precision of 1/16 inch with the markings they
selected. If you can find a ruler with tactile markings at every 1/16
inch, they will need to be so narrow that a fingernail is needed to count
them unless one has "super" tactile powers. It is even worse for .1 cm or
1 millimeter.

Standardized tests ask students to measure to the nearest tenth of a
centimeter, but this is unrealistic for the average Grade 3-12 braille
reader. None of the tactile rulers from APH (American Printing House for
the Blind) have a greater precision than .5 cm and most only have a 1 cm
precision. None of the tactile rulers from APH have a greater precision
than 1/8 inch and most only have 1/4 inch precision.

>From the BANA (Braille Authority of North America) Tactile Graphics
Guidelines:
"6.10 Measurement Tools
Actual braille rulers and protractors with raised marks do not register
small values. Rulers can provide an accurate measurement to within 1/4
inch (6 millimeters). Protractors can provide an accurate angle
measurement to within 5 degrees."

If your daughter really needs a ruler that will accurately measure to the
nearest millimeter (for example a wood working shop), I recommend the
Metric Click Rule. "It is an efficient tactile and auditory measuring
device that measures up to 20 centimeters with accurate increments of one
millimeter. Four extensions of 20 centimeters each allow measurement up to
one meter when added to the basic Rule... [It] is a fast and accurate
device for wood and tool set-ups... Measurements can be read either
tactually or aurally since a faint clock is emitted when each millimeter
is moved in or out." The Metric Click Rule with four extensions costs $80
and each additional 20 cm extension costs $6. It is available for purchase
from Community Advocates, Inc. Write Duncan Larsen at dlarsen at indra.com or
phone Nebraska at 402-486-3091 or Colorado at 303-666-8206. The mailing
address is: Community Advocates, Inc., PO Box 83304, Lincoln, NE 68501 or
PO Box 18672, Boulder, CO 80308. They also make a Click Rule (Standard)
that measures up to 12" with accurate increments of 1/16 of an inch. Three
12" extensions allow measurement up to four feet. The cost for it with
three extensions is $68. One 12-inch extension costs $7 and one 6-inch
extension costs $5.

Otherwise, all she needs is one of the many APH rulers mentioned above
that measures accurately to .5 cm or 1 cm and is available free with
federal quota monies.

Best wishes,
Susan

Susan A Osterhaus
Statewide Mathematics Consultant
Outreach Programs
Texas School for the Blind
  And Visually Impaired
1100 West 45th Street
Austin, TX 78756
Email: susanosterhaus at tsbvi.edu
Phone: 512-206-9305
Website: www.tsbvi.edu/math
Distance Learning: http://distance.tsbvi.edu/osterhaus_math_intro.html
Media Library: http://library.tsbvi.edu/

-----Original Message-----
From: Blindmath [mailto:blindmath-bounces at nfbnet.org] On Behalf Of Stores,
Mary A. via Blindmath
Sent: Tuesday, September 23, 2014 4:14 PM
To: Daniel Gillen; Blind Math list for those interested in mathematics
Subject: Re: [Blindmath] Millimeter ruler?

Hello,

Maybe this Braille ruler from MaxiAids would work:
http://www.maxiaids.com/products/1274/Tactile,-Braille-Ruler.html

Mary

-----Original Message-----
From: Blindmath [mailto:blindmath-bounces at nfbnet.org] On Behalf Of Daniel
Gillen via Blindmath
Sent: Tuesday, September 23, 2014 4:42 PM
To: Lynn Reed; Blind Math list for those interested in mathematics
Subject: Re: [Blindmath] Millimeter ruler?

dear Liz,

Over the many years that I've been through school, I have seen a few
different millimeter rulers that have tactile markings on them. Because,
of course, the resolution of braille dots is far greater than a millimeter
between each.(and the same is true for the size of the dots anyway), it is
more favorable to have the tactile markings along the gauge 4 mm and cm.
in many cases, I have also seen the inch side of the ruler divided into
what looks like sixteenths, which are almost always Mark tactually on
these devices. none of these, however, had any braille, although the
numbers were apparently small and raised. What I have been able to do,
though, was count the number of large markings first, and then the number
of smaller ones, the same way a sighted person might do it by inference.
Regardless, there was no actual readable text on the ruler itself.

Thank you,

sent from my iPhone

> On Sep 23, 2014, at 4:16 PM, Lynn Reed via Blindmath
<blindmath at nfbnet.org> wrote:
>
> Does anyone know of a place I can get a Braille/tactile millimeter ruler
for my daughter?
>
> Peace and Love to all!
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