CRANMER ABACUS INSTRUCTION
By: Carmen Willings
Updated October 28, 2017
The Cranmer Abacus was especially adapted for individuals who are blind to complete math operations. It differs from other abacuses in that it has a felt liner under the rods and beads to prevent the beads from sliding if the abacus is accidentally moved. It also differs in that it has raised vertical notches to guide in setting numbers and in using decimals and commas.
An abacus can be procured through quota funds from the American Printing House for the Blind if you have access to quota funds. There are several abacus that are available through other venders including Amazon. Although it is entirely appropriate to expose students at an early age to the abacus, prior to beginning formal instruction in the abacus, it is important to ensure that the student has foundational skills. These include a solid knowledge of addition facts, knowledge of place value, and the ability to define terms used for addition problems.
The abacus is a calculation tool but it should not be confused with a calculator. A better comparison is that it is used like paper and pencil for students with vision. The Cranmer Abacus was designed specifically for individuals who are blind. What makes it unique is the piece of soft fabric or rubber that is placed behind the beads so that they will not inadvertently move while the person performs calculations.
Once students have a basic understanding of addition and subtraction and has mastered their basic math facts, it is important to teach abacus skills to the student. It can't be stressed enough that a student needs to be able to do mental math with some ease before the abacus can be a useful tool. Talking calculators should also be avoided until a student understands mathematical processes. Students should ONLY be permitted to use a calculator if all students in the class are permitted to use their calculators. There is a common misunderstanding that the abacus is comparable to a calculator. A better comparison is its similarity to using fingers to count or paper and pencil.The abacus is a wonderful tool that can assist students in performing mathematical operations.
The abacus teaches mathematical skills that can't be replaced with talking calculators as it teaches the student the process of the calculation and leads to a better understanding of numbers and number sense. The Cranmer abacus is available through APH quota funds as well as Abacus Basic Competency: A County Method available from APH. For those who do not have access to quota funds, it can be purchased through a variety of retailers.
The Cranmer Abacus has thirteen vertical rods. On each rod are five moveable beads. A horizontal separation bar divides the top-most bead on each rod from the bottom 4 beads.
The zero position is when all the single beads are positioned at the top of the frame, and the four lower beads on each rod are on the bottom. There are raised dots along the separation line at each rod, and a raised vertical line after every third dot. The lines, called unit marks, serve as commas and decimal points depending on the math problem.
The first rod or column on the far right is the units rod. Each bead below the separation bar on this rod has the value of one. The single bead on that rod has a value of 5. The abacus is based on the decimal system so as you move to each rod on to the left the pattern continues. The second column is the tens column, the third column is the hundreds column and so on. Therefore, in the tens column, each bead below the separation bar has a value 10 and the single bead above the bar has a value of 50. This pattern continues up to the trillion column.
Setting & Clearing Numbers
Numbers are "set" when they are recorded and "cleared" when they are removed or erased.
Teachers of Students with Visual Impairments (TVIs) may need refreshers and practice in using the abacus as they can go years without having a student who requires this type of instruction. Thankfully, there are tools available to refresh skills.There are different methods to teaching the abacus, the following resources provide instruction in some of these methods. Additionally, YouTube videos are available online that instruct in how to perform various calculations.
Abacus Made Easy Second Edition: A Simplified Manual for Teaching the Cranmer Abacus This manual, available from APH, provides simplified instructions in setting and clearing numbers and perform operations including: addition, subtraction, multiplication, division, decimals, fractions, percent, and square roots on the abacus.
Abacus Basic Competency: A Counting Method
This instruction manual, available from APH, teaches abacus skills in the four basic math operations. This abacus instructional system uses the Counting Method instead of the traditional indirect method.
UAbacus App for iPad, iPod, iPhone
This app, which is FREE, allows the user to practice addition and subtraction on a simulated abacus.
Susan Osterhaus, along with other TVI's, have math resources and videos on abacus use and instruction on Texas School for the Blind.
Sign up for free membership to access the FREE downloadable templates, handbooks and handouts on the Printables page. Simply click on the Log In | Register link in the navigation bar. If you haven't joined yet, you will be prompted to create a password.
TVI's Guide to Teaching the ECC: An Activities Based Curriculum for Teaching Students who are Blind or Visually Impaired
Written specifically for fellow itinerant Teachers of Students with Visual Impairments (TVI’s), this book consists of over 400 activities and topic areas of discussion for instructing students in the Expanded Core Curriculum. The activities are age-neutral and multi-sensory and therefore can meet the needs of the broad range of students served on an itinerant caseload serving. The activities can be individualized to the students various learning modalities and scaffold in order to challenge students but ensure success. Select those activities that align with the student’s learning objects based on the student’s unique visual needs and academic and developmental level.
The core activities listed in the Activity section can be adapted to each thematic unit. These include:
In addition to the core activity areas, each of the 32 Thematic Units incorporates additional unique ECC concepts and skills providing you with a years’ worth of activities. These units are cyclical and can be used repeatedly to help students build on prior knowledge and develop a deeper understanding of concepts. Each unit includes suggestions for activity adaptation associated with the unit. These include lists of objects, possible community based experiences, environmental print, poems, children & young reader books, children's songs, pop culture songs, movies, and websites.
Unique Concepts within the Units include:
Although the intended audience of this resource is fellow Teachers of Students with Visual Impairments, special education teachers may find these activities beneficial to the students in their classrooms as the activities are multisensory and include life skills and concepts needed by all students. This resource, however, is not intended to take the place of a Teacher of Students with Visual Impairments (TVI). Readers are advised to consult their own TVI’s regarding instruction in the ECC and the unique visual needs of the student’s served in their programs.
Note: This curriculum is a digital pdf download. Once you make your purchase you will be directed to an order confirmation page where you will find the download link. This download will also be included on the receipt sent to the email address you provide. The pdf download can be found directly under the order number.
Each download is intended for single instructor use per copyright. Thank you for helping me preserve the content and not distributing copies to third parties.
Digital pdf download: 364 pages (11 pt font)
Publisher: Teaching Students with Visual Impairments
Author: Carmen Willings
Visual Efficiency & Magnifier Fluency Grab & Go ECC Supplements
This workbook is a pdf download that can be printed on demand for use with students. It contains five different types of worksheets for developing visual motor skills and near magnifier fluency skills particularly with the use of a video magnifier. As a supplement to the TVI’s Guide to the ECC, the worksheets correspond to each of the 32 ECC Thematic units. The worksheets, along with a list of environmental print for each thematic unit, are designed to help students refine their visual motor skills while reinforcing ECC concepts presented in the thematic units.
Visual Efficiency & Near Magnifier Fluency Worksheet Details:
Digital pdf download: 210 pages
Publisher: Teaching Students with Visual Impairments
Author: Carmen Willings