Fourth Edition
This edition first published 2017
© 2017 John Wiley & Sons, Ltd.
Edition history: 1e Whurr Publishers Ltd, 1993; 2e Whurr Publishers Ltd. 1998; 3e John Wiley & Sons, Ltd. 2007
Registered Office
John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK
Editorial Offices
350 Main Street, Malden, MA 02148‐5020, USA
9600 Garsington Road, Oxford, OX4 2DQ, UK
The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK
For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley‐blackwell.
The right of Steve Chinn and Richard E. Ashcroft to be identified as the authors of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.
Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.
Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book.
Limit of Liability/Disclaimer of Warranty: While the publisher and authors have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. It is sold on the understanding that the publisher is not engaged in rendering professional services and neither the publisher nor the author shall be liable for damages arising herefrom. If professional advice or other expert assistance is required, the services of a competent professional should be sought.
Library of Congress Cataloging‐in‐Publication data applied for
Paperback ISBN: 9781119159964
A catalogue record for this book is available from the British Library.
Cover image: Violka08/Gettyimages
Dedicated to the memory of our dear friend and colleague, Lyn Rawles
Steve Chinn’s newest edition of the 1993 Chinn and Ashcroft book Mathematics for Dyslexics is an important and timely addition to the dyscalculia or mathematical learning disabilities literature. As Chinn notes in his introductory chapter, basic and applied research on dyscalculia has lagged behind that of dyslexia for decades. The gap has closed somewhat in recent years, but children’s and adults’ struggles with basic mathematics remain relatively neglected. This seemingly benign neglect can have largely unrecognised long‐term consequences for students and ultimately the communities within which they reside (National Mathematics Advisory Panel, 2008), independent of their reading skills, cognitive abilities, or ethnic background. For instance, adults who have difficulty solving word problems that require whole number arithmetic, fractions, simple algebra and measurement have compromised employment prospects (Bynner, 1997; Parsons and Bynner, 1997; Rivera‐Batiz, 1992), and difficulties in other areas of life that require quantitative knowledge (e.g. Reyna et al., 2009).
These adults would be considered innumerate – either because of an underlying difficulty with mathematical learning (e.g. low working memory capacity), poor instruction, poor motivation, or some combination – and now include 20–25% of adults in the United Kingdom and the United States. Unfortunately, the path to adult innumeracy starts early, probably before the beginning of formal schooling (Duncan et al., 2007; Ritchie and Bates, 2013). One recent study suggested that children who start school with a poor understanding of Arabic numerals, the magnitudes they represent and the relations among them [e.g. 7 = (6 + 1) = (5 + 2) = (4 + 3)] score poorly on numeracy tests as adolescents (Geary, Hoard, Nugent, and Bailey, 2013). In this study, six‐year‐olds who started school in the bottom 15–20% in this number knowledge were four times more likely to score as innumerate in adolescence on tests that have been shown to predict later employability and wages in young adults. By eight years of age, these at‐risk children learned basic arithmetic as quickly as other children, but they never narrowed the school‐entry gap. This is not to say that they could not catch up with the right remediation approaches, but it does emphasise the importance of catching and addressing potential difficulties early.
The questions then become, what are the early precursors of school‐entry quantitative knowledge and what are the key mathematical competencies that must be developed to ensure students have functional numeracy skills by the time they leave school? The foundation is a solid understanding of Arabic numerals and the relations among them, and in Chapter 5 Chinn does an admirable job of identifying these core number skills and how they should become elaborated over the course of schooling (i.e. organized around the base‐ten system). Strong arithmetic skills are just as important as the number skills on which they are built, and Chinn devotes chapters 6–14, inclusive, to various aspects of arithmetic, from learning the multiplication tables (or learning backup strategies for children who have difficulties memorising facts), to rational numbers (i.e. fractions, decimals, and percentages). Each of these chapters is organised around learning issues detailed in the introductory chapters and is presented with detailed examples, explanations and advice on how to approach the instruction of each of these critical topics. The final chapters expand the discussion to applied topics, such as time telling, lay out the basics for approaching algebra and geometry, and provide very useful teaching tips.
In all, this is not just a much‐needed book for remedial approaches to dyscalculia, but a book that identifies critical number and arithmetic skills that are important for all students to learn. The focus of course is on instruction and remediation, and the approaches detailed herein will be particularly useful for instructing children with one form of cognitive difficulty (e.g. in memorizing basic facts) or another (e.g. poor working memory capacity), but these same approaches should be helpful for any child who is struggling with basic mathematics. Our best estimate, at this point, is that any child in the bottom 25% on mathematics achievement tests is in need of remedial attention, whether or not they have cognitive difficulties, and this book provides the roadmap for this remediation.