Calculator Riddles

by David A. Adler

Book Overview

Answers to riddles are found by solving related math problems and turning the calculator upside down. This description may be from another edition of this product.

• Format: Hardcover
• Language: English
• ISBN: 0823411869
• ISBN13: 9780823411863
• Release Date: September 1995
• Publisher: Holiday House
• Length: 1 Pages
• Weight: 0.60 lbs.
• Dimensions: 0.4" x 6.2" x 8.8"
• Age Range: 9 to 12 years
• Grade Range: Grades 4 to 7

Customer Reviews

Fun for the young, may be confusing for grades 5 and up.

As stated, the riddles are fun, and they encourage young kids to get used to punching buttons on a calculator. But beware of getting this book for kids in grades 5 and above, since the math equations work only if a child mindlessly follows the operations in the order listed. For students learning the rules for "order of operations" (like my son's 5th grade), these equations are not in proper form. For example: "I can be big. I can be small. But big or small, I weigh nothing at all. What am I?" The answer says: 20 x 25 - 37 x 8. You can get the intended answer (3704 or HOLE) by following the steps exactly as written. But if you read this equation by the mathematical rules learned in pre-algebra or higher, you'll know that all multiplication steps should be done BEFORE addition steps and you'll get the wrong answer! You'll get (20 x 25) - (37 x 8) = 500 - 296 = 204. My son's calculator is programmed to follow these math rules, so it gives the wrong (but mathematically right!) answer. Few kids (or adults!) will care about my objection, but I wanted to point it out so that math teachers don't contradict their own lessons by using these riddles for classroom fun. Of course, you can steal the riddle and re-write the equations using parentheses to be mathematically accurate (as I did)! (20 x 25 - 37) x 8 = 3704 or HOLE.

Making math fun

Want to show your kids or students just how fun math can be? Students of all ages will thoroughly enjoy finding the answers to these crzay riddles by doing the math problems, then turning the calculator upside down to read the answer. This is a great item to keep in the car with a calculator to keep kids busy while on a long trip or running errands. You'll wish there were more of these books when you finish the final riddle.