Diffy

This interactive Java applet provides students with practice in subtraction and pattern recognition. Starting with four numbers in the corners of an outside square, students find the differences (larger minus the smaller) between the pair of numbers on each side of the square. After correctly completing each square, they repeat the process for the next inner square, until all squares are complete. Students can explore the patterns that emerge as they work toward the center square. Users can choose to work with whole numbers, integers, fractions, decimals, or money. They may also create their own problems by selecting the four starting numbers for the outside square.
(16 Comments)
Contributed by: National Library of Virtual Manipulatives, Publisher
Math TopicMeasurement, Number Sense, Decimals, Fractions, Basic Operations, Number Concepts, Algebraic Thinking, Mathematical Practices, Mathematical Processes
Grade Level1, 2, 3, 4, 5
Resource TypeActivity, Game, Interactive Media

• Additional Information
• AudienceLearner
• LanguageEnglish (USA)
• Education Topic
• Interdisciplinary Connection
• Professional DevelopmentNo
• ContributorNational Library of Virtual Manipulatives, Publisher
• Publication Date1999
• Rights(c) 1999-2010 Utah State University
http://nlvm.usu.edu/en/nav/copyright.html
• AccessAvailable for purchase, Free access
• Standards
• Common Core State Standards for Mathematics

Select a standards document:

• User Comments
• Practice and Patterns
By Uncle Bob on 04/24/2012 - 12:55
• I enjoyed using this app once I got used to keying in the differences. I can imagine the students sticking with this to see the final patterns which have several flavors. I prefer the keystrokes (enter, and tab for fractions) and just follow their prompts around the network for mouse-free playing.
• Great Logic
By TRodgers on 08/20/2012 - 17:18
• Really excellent for working with fluency. Students having trouble may benefit from having a number line while they work.
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