Magic Grid Trick

Introduction: Magic Grid Trick

Effect: Without looking, you tell a volunteer to circle any number in a grid from 1-25 and cross out every other number in its row and column. Then you say to do it four more times without using a crossed-out or circled number. Next, you tell them to add the five circled numbers together and keep the total secret. Finally, you reveal the total without looking at what numbers your volunteer picked.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Setup

Draw a grid like I just showed you, and write the number 65 on some paper and put it in your pocket.

Step 2: How It Works

Some math thing says that if you do that, it will always equal 65. To perform, draw or print a grid and hide a piece of paper with "65" somewhere. Then just say somthing like what I said in the intro.




Magic Grid Trick Done!  

Be the First to Share

    Recommendations

    • Toys and Games Challenge

      Toys and Games Challenge
    • Backyard Contest

      Backyard Contest
    • Silly Hats Speed Challenge

      Silly Hats Speed Challenge

    Discussions