Sydney thinks of a number.
She multiplies this number by 6 then subtracts 8.
Her answer is 40. What was Sydney's original number?
Sydney's friend thinks of a number.
She then does the following operations:
Multiply by 3, subtract 6, multiply by 3 then add 50 (in that order). She finds that the number she ends up with is 13 times her original number.
What was Sydney's friend's original number?
Change NumbersEasier Questions
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Have you read Craig's book yet?Craig Barton must surely be the voice of Mathematics teachers in the UK. His wonderful podcasts interviewing the industry experts have culminated in this wonderful book. As Craig says: "I genuinely believe I have never taught mathematics better, and my students have never learned more. I just wish I had known all of this twelve years ago..." more... "How I wish I'd taught Maths" is an extraordinary and important book. Part guide to research, part memoir, part survival handbook, it’s a wonderfully accessible guide to the latest research on teaching mathematics, presented in a disarmingly honest and readable way. I know of no other book that presents as much usable research evidence on the dos and don’ts of mathematics teaching in such a clear and practical way. No matter how long you have been doing it, if you teach mathematics—from primary school to university—this book is for you." Dylan Wiliam, Emeritus Professor of Educational Assessment, UCL. 
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Teacher, do your students have
access to computers? 

Here a concise URL for a version of this page without the comments.
Here is the URL which will take them to the Think Of A Number exercise.
Here is the URL which will you to our eQuation Generator which provides unlimited practice solving linear equations.