Cranmer Abacus InstructionBy: Carmen Willings
teachingvisuallyimpaired.com Updated June 9, 2019 The Cranmer Abacus was specially 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 abaci that are available through other vendors 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.
An abacus is a calculation tool but it should not be confused with a calculator. A better comparison is that it is used as 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 have 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. An 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. Abacus BasicsThe 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.
Zero Position
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 NumbersNumbers are "set" when they are recorded and "cleared" when they are removed or erased.
Additional Resources...
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 of teaching the abacus, the following resources provide instruction in some of these methods. Additionally, YouTube videos are available online that instruct on 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. TSBVI
Susan Osterhaus, along with other TVI's, have math resources and videos on abacus use and instruction on Texas School for the Blind. |
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TVI’s Guide to Teaching the ECC: An Activities Based Curriculum for Teaching Students who are Blind or Visually Impaired The TVI’s Guide to Teaching the ECC is a digital pdf available for download. It is designed specifically for fellow itinerant Teachers of Students with Visual Impairments (TVI’s), and 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. 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. In addition to the book, the following two supplements are included: ·      TVI’s Guide to the ECC Concept Checklist ·      TVI’s Guide to the ECC Activities Checklist For complete product details and additional images, visit the TVI's Guide product page. TVI's Guide to the ECC Product details ·      Digital pdf download: 346 pages (11 pt font) ·      Publisher: Teaching Students with Visual Impairments ·      Author: Carmen Willings ·      Language: English Visual Efficiency & Near Magnifier Fluency Worksheets: TVI's Guide to the ECC Grab and Go Supplements The Near Magnifier Fluency Worksheets is a Grab and Go supplement to the TVI's Guide to Teaching the ECC. 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 companion 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.  For complete product details and additional images, visit the Visual Efficiency & Near Magnifier Product Page. Visual Efficiency & Near Magnifier Fluency Worksheet Details: ·      Digital pdf download: 210 pages ·      Publisher: Teaching Students with Visual Impairments ·      Author: Carmen Willings ·      Language: English Thematic Keyboarding & Braille Fluency and Maintenance Worksheets: A TVI’s Guide to Teaching the ECC Grab & go Supplement The Thematic Keyboarding & Braille Fluency and Maintenance Grab and Go ECC worksheet packet is a print on demand workbook that contains worksheets in print and simulated braille to use for data collection. Present the student with a hard braille copy and use the worksheets to document accuracy and fluency in reading braille. As a companion to the TVI’s Guide to the ECC, the worksheets correspond to the ECC Thematic activities presented in the curriculum guide. These word lists and sentences will help the student refine their keyboarding or braille reading skills while bridging ECC concepts presented in the thematic units. Although the lists and passages can be produced using a manual braillewriter, you may also copy and paste the passages into any braille translation software for quick production on an embosser. They may also be entered into a typing program such as APH’s Talking Typer to build keyboarding fluency. For complete product details and additional images, visit the Thematic Keyboarding & Braille Fluency & Maintenance Product Page Thematic Keyboarding & Braille Fluency Worksheet Details: ·      Digital pdf download: 338-page print and simulated braille worksheets ·      Publisher: Teaching Students with Visual Impairments ·      Author: Carmen Willings ·      Language: English Thematic Vocabulary Cards and Checklists: Grab & Go ECC Supplement The Thematic Vocabulary Cards and Checklists Grab and Go ECC supplement is a 446 page pdf downloadable print on demand workbook that includes 2940 vocabulary card on 3 1/2" x 2" templates divided by each of the 32 Thematic Units along with a checklist of each unit words in print and simulated braille. As a companion to the TVI's Guide to the ECC, the vocabulary cards correspond to the ECC Thematic activities presented in the curriculum guide. Additional Use: Teachers of Students with Visual Impairments can have a extremely varied caseloads. It is possible to go several years without having a student on your caseload who requires braille instruction. Like other skills, if you do not practice your braille regularly, it is easy to lose those skills. Use these checklists and cards to maintain your braille skills. Fold the checklist along the line dividing the print from the braille. Choose to either read the print and produce the word in braille using a braillewriter or read the simulated braille and decode it. Finally, these vocabulary cards and checklists may be used with family members or peers who are interested in learning and practicing the braille code. For complete product details and additional images, visit the Thematic Vocabulary Cards & Checklists Product Page Thematic Vocabulary Cards and Checklists Details: ·      Digital pdf download: 446-page print on demand resource ·      Publisher: Teaching Students with Visual Impairments ·      Author: Carmen Willings ·      Language: English BONUS! Lotto Cards The LOTTO Cards Grab and Go Supplement includes 37 theme related unit cards along with activity suggestions that support activities within the TVI's Guide to Teaching the ECC. On My Way File Folder Cards Print and use these cards to represent locations the student may visit that are related to the current thematic unit. Use these with the On My Way File Folder Game outlined in the TVI's Guide to Teaching the ECC p. 27. NEW! Access to TVI's Guide Bonus Membership Pages Note: All products are digital pdf downloads. 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. If you encounter any difficulty, please let me know and I can assist you. |
