Number Fun

Contents

Plus or Minus One Through Nine

Practice Pages

The Puzzle

Extra Numbers from 211 to 867

Answers to Numbers

1 through 210

Answers to the Extra Numbers over 210

About this Book

This book is like 210 individual puzzles while at the same time it is one very large puzzle.

Things needed to play this game.

1. A hand held calculator.

2. A pencil with a good eraser.

3. A good amount of patience.

4. At least some interest in puzzles.

Age requirement

Good for any age if you can add and subtract and use a calculator. To try this without a calculator would require reams of scrap paper and lots of time.

About the author

Mr. Daniels holds a Bachelors and a Masters Degree from the University of Delaware. He has been a member of MENSA for the past 25 years. He is presently retired from 30 years of teaching.

Plus or Minus One Through Nine

RULES

You may only use a + or a – sign in this game. They can be added any place in each line. All nine numbers must be used for each answer, and kept in numerical order. For example 1 + 23 – 4 equals 20 plus the other five numbers. Another example 1 + 2 + 3+ 4 + 5 equals 15 plus the other four numbers. You may even use 1 2 3—4 5 6 + 7 8 9 = 456. This is only an example that you will not need in the first part of this book. Using a calculator you can do something like this 1 – 2 – 3 + 4 equals 0 plus the other five numbers. Also 1 2 3 – 4 5 + 6 7 +8 9 = 2 3 4. Minus 1 (-1) in the beginning is permitted like the following example. –1 + 2 + 3 4 etc. with the other five numbers. If you do not understand the rules take a quick glance at the answer pages, you will not get any answers by glancing at these pages because they are too involved to memorize.

It is not as hard as it first appears because you will soon find patterns which will lead to many easy answers. It took the author about six hours to find all the answers up to 210.

There is more than one way to make some of these sets to give the right answer. In these cases your calculator will be the judge. The answers in the back of the book are only one way to do each, and only meant to show that it can be done. Your answer does not have to match the answer given here as long as your calculator tells you the answer is correct.

This set of calculations ends with 210 only because at that point there will be some numbers that are impossible, which would leave blanks. However, for your own satisfaction you could find many other numbers above 210 , in fact some of these are included in the back of this book. You may become addicted to this the longer you play.

A starting point might be to add a plus or minus to each number possibly alternating like this example. 1 – 2 + 3 – 4 + 5 – 6 + 7 – 8 + 9 = 5. Then go back and change any minus to a plus and you will get another of the answers ( etc. etc.). If you are not used to minus numbers the use of a calculator will solve that. In the beginning when doing the lower numbers there will be several correct answers to