### Read as if you edit

Previously, in one of my posts I wrote that I tend to read books as if I proof-read or edit them. There are a number of advantages in doing so. For example, reading books end to end ensures deeper understanding of the content. Attempting to solve each exercise in a book is also a positive thing to do, because even if you do not solve it, you can get a valuable insight just because you tried hard to solve an exercise. When you follow this advice, after a book or two this starts to happen automatically to you and you can’t help, but spot spelling mistakes, wrong diagrams used or mistakes in formulas etc.

To see a real example of the above suggestions let’s look at the ** All Things Being Equal** book by John Mighton founder of the JUMP math teaching method. This book is not a math textbook, but a book about how math can be taught to kids. The main idea is that math can be taught to an average person and it doesn’t take a genius to like math and be productive in it. There are a number of exercises that John Mighton provides in the book to showcase his approach of teaching math at school. I’ve tried each one of them and lo and behold found a number of mistakes in the book. One mistake was spotted by my daughter. And this is exactly what I want to write about next.

### Some concrete examples

I’ve got a softcover edition of the book, ISBN 9780735272903. On page 201 of this edition John Mighton provides an example of how a simplified Sudoku version can be accessible and enjoyable to kids. The regular Sudoku puzzle 9 by 9 cells looks as follows. Each row and column in the table below should contain all of the digits from 1 to 9, when no digit can appear more than once.

A simplified version is 4 by 4 cells, which is easier for kids to start to play with. Now, I’ll provide all four puzzles on the page 201 of the book.

### Puzzle #1

This puzzle is solvable, so let’s move on to the next

### Puzzle #2

This puzzle has a mistake in it. Try to find it yourself or jump to the end of the post for an answer.

### Puzzle #3

It’s solvable. Move on.

### Puzzle #4

This puzzle has a mistake in it and my daughter, who was in Grade 2 at the time, was able to spot the mistake.

*Pay attention, that there cannot be a duplicate value on any row, column in the table.*

### Closure

When you spot and collect a certain amount of mistakes it’s good to inform an author of the book or a publisher about them. Usually, authors are grateful if you report mistakes to them and it could even result in a friendship or a nice communication with them.

It wasn’t the case with *All Things Being Equal* where there was no response when I sent the errata to the JUMP Math contact email. So I sent an email directly to the Vintage Canada who is the publisher of this book.

So take care and report mistakes, who knows where it will take you.

The 4×4 sudokus are great for children. When I hosted a games club at Duc D’Anville Elementary, we replaced the numbers 1,2,3,4 with 4 different colors and used Lego pieces of these colors to populate the grid, ie no numbers used.

The kids especially liked the from-scratch 4×4 color sudoku building when they realized they could create a partial one and then let a friend try to complete it, and vice versa.

See https://funfairview.wordpress.com/2019/10/17/sudoku-the-creative-way/

Thank you for the 4×4 color sudoku idea.