Francis Lai - Sudoku: Explaining the Fifteen Steps of the Francis Rules for Sudoku

SODUKO

USING THE

Francis Rules for SUDOKU

Dr. Francis Lai

Copyright 2006 Dr. Francis Lai

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, without the written prior permission of the author.

Note for Librarians: A cataloguing record for this book is available from Library and Archives Canada at www.collectionscanada.ca/amicus/index-e.html

ISBN 1-4120-8023-1

ISBN 978-1-4122-4040-6 (ebook)

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Contents

This book illustrates the fifteen easy rules for solving any Sudoku Challenge, using the conventional cell references of Microsoft Excel that are so familiar to every computer user. The book is meant for beginners to the Sudoku Challenge. If you are not a beginner, you may wish to contact the author for a simple test to see which of the ten levels of competency that is most suited to your present stage of Sudoku experience.

This examples and challenges in this book are therefore confined to the first six levels of Dr. Francis Lais ten levels of competency, namely:

Level 1: Extremely Easy

Level 2: Very Easy

Level 3: Moderately Easy

Level 4: Fairly Easy

Level 5: Easy

Level 6: Getting Taxing

Level 7: Moderately Taxing

Level 8: Fairly Taxing

Level 9: Taxing

Level 10: Very Taxing

We shall leave the discussion on the more Taxing Levels to a further book in this series.

However, should readers desire to go into the Sudoku Challenges at the various Taxing Levels, they should contact the author at easy.. com

Readers can also request at this e-mail address for a self-test to determine their current levels of Sudoku competency.

SHOULD result in an improvement both in the level of competency and in the speed with which any Sudoku Challenge can be solved.

This book is published by:

Trafford Publishing 2333 Government Street, Suite 6E Victoria, BC Canada V8T 4P4 Phone: 250-383-6864 Toll-free: 1-888-232-4444 (from Canada & USA) Fax: 250-383-6814 e-mail: . com

Visit the online bookstore at www. trafford. com

nd February 2006

ISBN: 1-4120-8023-1.

Dr. Francis Lai can be contacted at: easy.. com

Dedication

This book is written especially for:

Yok Lin Lai Pauline, Roger, Daniel and Oliver Shew Wendy Lai Mark and Ahryn Thomas

Molly Shepherd Glen and Rebecca Roser Will Laiwho have all encouraged the publication of this book in their own special ways.

ABOUT THE AUTHOR

Dr. Francis Lai is a chartered surveyor qualified in two disciplines of the Royal Institution of Chartered Surveyors-Property Valuation and Quantity Surveying. Additionally, he holds a doctoral degree in inter-religious dialogue, specializing in the works of Wilfred Cantwell Smith.

Dr. Lai has always been involved in education and training of young professionals in the real estate marketing and the property consultancy fields.

Dr. Lais love for logic springs from his childhood interest in Mathematics. His art of using simple words to explain complicated ideas and concepts in a logical fashion has commanded the love and respect of many of his students in Singapore, Thailand and New Zealand.

Readers of this latest work of Dr. Lai will find for themselves how easy it is to follow the logic involved in the art of solving the latest puzzle craze-the SUDOKU Challenge, using the

A Sudoku Challenge Chart is like an Excel Spreadsheet with 81 cells-nine (9) rows and nine (9) columns.

Every cell is named by its column alphabet followed by its row number and thus the Chart starts at cell A1 at the top left hand corner to I9 at the bottom right hand corner.

There are nine boxes in the Chart. Each box has nine (9) cells. Box 1 has the cells A1, A2, A3, B1, B2, B3, C1, C2, C3 and can be referenced as A1: C3.

Box 2 therefore is referenced as D1: F3; Box 3 as G1:I3; Box 4 as A4: C6 and so on until Box 9 as G7: I9.

The simple goal for a Sudoku Challenge is to fill in the cells with digits 1 through to 9 such that:

The digits in each row are not the same, in other words, every digit in a row is different-nine digits to fill nine cells with no repeated digit;

The digits in each column are not the same, in other words, every digit in a column is different-nine digits to fill nine cells with no repeated digit;

The digits in each box are not the same, in other words, every digit in a box is different-nine digits to fill nine cells with no repeated digito

To start, a Sudoku Challenge Chart has some cells already filled up with digits. As a general rule, the more digits that are exposed in a chart, the easier the Challenge. An extremely easy Level 1 Challenge, meant for primary school children has as much as 58 cells already filled with digits leaving the children to logically work out the remaining 22 cells. This Level 1 Sudoku Challenge Chart is illustrated below:

It is easy to solve this Level 1 challenge. Why not try this out for yourself?