Here’s a new original puzzle that goes along with the Thursday’s puzzles from the past two weeks, Even’s Only and Odd’s Only. In the same theme, this is another great challenge for everyone. It emphasizes combining the first four prime numbers (2,3,5 and 7) with addition, subtraction, multiplication and division using the rules of order of operations. Many falsely believe that 1 is a prime, but sadly it is not (how lonely to be 1 – excluded even from the primes).

The rules are simple:

1. Use only the numbers 2, 3, 5 and 7

2. Use each number once and only once

3. Use any of + – x / to combine the numbers

4. Use parenthesis () as desired

5. Following rules 1-4, make the numbers 0-9

#### For example, “10” can be made as “5 x 3 – 7 + 2″. In this example, each number (2,3,5,7) was used once and only once as required. There are other ways to make “10” which would also work.

I put together a little interactive program for this puzzle. You can enter your answers for each number and then select check. Your answers will be scored and a response provided (e.g. “got it!” or “need to use 2,3,5 and 7″). Give it a try and let me know what you think. Click here for a pdf file.

I hope you enjoy this puzzle. Good luck and pass it onto others who may enjoy them!

In order to use the interactive puzzle, you need to have adobe flash enabled.