Cover image for Mental math challenges
Mental math challenges
Lobosco, Michael L.
Personal Author:
Publication Information:
New York : Sterling Pub., [1999]

Physical Description:
80 pages : color illustrations ; 26 cm
Presents hands-on tasks and do-it-yourself activities using simple materials and inexpensive supplies demonstrating logic and reasoning abilities in mathematics.
General Note:
"A Sterling/Tamos book."

Includes index.
Format :


Call Number
Material Type
Home Location
Item Holds
QA40.5 .L62 1999 Juvenile Non-Fiction Open Shelf

On Order



Imagine guessing someone's age with just three simple questions, totaling up any five shopping items faster than a calculator, or changing the color of a toothbrush in a flash. You can--with these colorful math challenges. All you need are some readily available materials, a sense of fun, and the desire to experiment. Do instant calculations and mind reading, vanishing tricks and illusions, precision measuring without instruments, and solitaire pastimes. Create beauty with circles and flexagons--and make a terrific paperweight with a tetrahedron! With just a little patience and effort, you'll meet every one of these challenges. 80 pages (all in color), 8 1/2 x 10. NEW IN PAPERBACK

Reviews 1

School Library Journal Review

Gr 5 Up-Packed with full-color photographs and diagrams, this fascinating volume offers detailed instructions on the construction of mathematical models of two and three dimensions and related activities. The 37 projects are grouped into six categories: "Beauty with Circles and Flexagons," "Instant Calculations and Mind Reading," "Vanishes and Illusions," "Precision Measuring without Instruments," "Math in Everyday Life Situations," and "Solitaire Games." Additional challenges and all solutions are provided. The required materials can be found around the house or purchased inexpensively. The activities range from the simplicity of the Buffon Toothpick Experiment, for which all that is required is a box of toothpicks, a large sheet of paper, a pencil, and a ruler, to the more complicated Floating Sphere and 3-D Stadium Design. The math concepts used in these mental workouts also cover a wide range of abilities. Students will be drawn to this colorful book because of its attractiveness, its challenges, and its hands-on approach.-Linda Wadleigh, Oconee County Middle School, Watkinsville, GA (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.

Table of Contents

Introductionp. 4
Beauty With Circles and Flexagonsp. 5
Floating Spherep. 6
3-D Stadium Design From Concentric Circlesp. 9
Tetraflexagon--An Unusual Flexagonp. 13
Transforming Magical Shapesp. 16
Tetrahedron Makes a Terrific Paperweightp. 18
Mind-Boggling Flexatubep. 20
Instant Calculations and Mind Readingp. 23
Amazing Number 143p. 24
429 Product Reveals Chosen Numberp. 26
Hyakugo Gen--Famous Japanese Formulap. 27
The Confident Gamblerp. 28
Amazing Prediction of Top Card in Addition Trianglep. 30
The Odd King's Odd-Numbered Problemp. 33
Choose Your Fortune Mind-Reading Featp. 34
Split-Second Multiplication by Cutting Stripp. 39
Lightning Additionp. 40
Add Five Items Faster Than a Calculatorp. 41
Vanishes and Illusionsp. 43
The Case of the Missing Dollarp. 44
Another Case of the Missing Dollarp. 45
Toothbrush Changes Color in a Flashp. 47
2-3 Prong Illusionp. 48
65 Squares, 64 Squares, 63 Squaresp. 50
Precision Measuring Without Instrumentsp. 51
Measuring Small Round Objects With a Paper Micrometerp. 53
Precise Line Measurement With a Diagonal Scalep. 54
Measuring the Height of a Flagpole With a Mirror and Yardstickp. 55
Math in Everyday Life Situationsp. 56
The Smart Greek's Formula and the Road Builder's Dilemmap. 57
Two Squares Always Make a Larger Squarep. 59
Solve Algebra Problems Instantly With Geometry Cardp. 60
How Many Paths Can You Take to Spell Your Namep. 62
The Many Different Paths From John's Housep. 65
Find the Area of This Unusual Gardenp. 66
Solitaire Gamesp. 68
Lucky Sevenp. 69
Twenty Triangles Make a Perfect Squarep. 70
Moving Nine Pennies in Nine Movesp. 71
Buffon Toothpick Experimentp. 73
Japanese Very Different Tangramsp. 74
Make a Square With Only Five Piecesp. 77
Create a Perfect Star and Play the Numbers Gamep. 78
Indexp. 80