In article <firstname.lastname@example.org>, ted walko wrote: > My son's teacher gave him diffy puzzles (specifically puzzle #3) to > solve. Curious, if anyone knows of a comprehensive resource (text > book) where I can get more of these puzzles?
Please give us more information about what a "diffy puzzle" is. What age or grade is your son? Where does he go to school? (I'm guessing somewhere in the USA from the .com address.) Since his teacher gave him the puzzle, he or she may be the best contact to find out where the puzzle came from.
Unfortunately, "diffy" is a rather generic slang term used to abbreviate "difficult", "differential", and "different", so is not much use in identifying the puzzle you mention.
The only relevant things I found on the web were
Name of activity: DIFFY Grade level: 2 - 8 Source of activity: Smith, Seaton E. , Jr. & Backman, Carl A. (Ed.). (1975). Games and Puzzles for Elementary and Middle School Mathematics: Readings from the Arithmetic Teacher. Reston, VA: National Council of Teachers of Mathematics.
Diffy--This game was created by Herbert Wills. Place a 2-digit number in each of the four corners of the Diffy game sheet as shown in Figure #. Subtract the two numbers from each other and place the difference between them. Continue in this manner until you get to all zeros or complete the entire game sheet. [The web page did not include the referenced figure.]
------------------------------------------------------------ Kevin Karplus email@example.com http://www.soe.ucsc.edu/~karplus Professor of Biomolecular Engineering, University of California, Santa Cruz Undergraduate and Graduate Director, Bioinformatics (Senior member, IEEE) (Board of Directors, ISCB starting Jan 2005) life member (LAB, Adventure Cycling, American Youth Hostels) Effective Cycling Instructor #218-ck (lapsed) Affiliations for identification only.