CK-12 Foundation
Ck 12: Algebra: Guess and Check, Work Backward
[Free Registration/Login may be required to access all resource tools.] Learn how to solve problems using guess and check and by working backward.
CK-12 Foundation
Ck 12: Algebra: Guess and Check, Work Backward
[Free Registration/Login may be required to access all resource tools.] Develop and use the strategies of guess and check and work backward.
Texas Instruments
Texas Instruments: Numb3 Rs: Thinking Backward
Based off of the hit television show NUMB3RS, this lesson gets students to work backward, or to find the inverse, of given problems. Two type of problems are presented: one is the graph of a parabola, and the other involves bank shots on...
CK-12 Foundation
Ck 12: Algebra: Guess and Check, Work Backward
[Free Registration/Login may be required to access all resource tools.] Solve word problems using the guess, check, and revise strategy.
Other
Math Stories: Working Backwards
At this one page site you can work through step by step a sample problem that illustrates the problem solving strategy for "Working backwards." The answer is right there to help you check your thinking.
University of Cambridge
University of Cambridge: Nrich: Two Stones Game
Sharpen your problem-solving and strategy skills while playing the interactive game, Two Stones. The rules are simple, but the game requires some thinking if you want to beat the computer. Watch as the play proceeds to see what it takes...
University of Cambridge
University of Cambridge: Nrich: Daisy Game
Sharpen your problem solving and strategy skills by playing this interactive game. The game's rules are simple, but play requires some thinking if you want to beat the computer. You can change the settings and see if your strategy works...
University of Cambridge
University of Cambridge: Nrich: Game Counter Roundup
Sharpen your problem solving and strategy skills playing this interactive game, Counter Roundup. The rules are simple but the game requires some thinking if you want to beat the computer. There is a "Get Printable Page," link at the top...
CK-12 Foundation
Ck 12: Elem Math: Mixed Operations Subtraction and Addition I Word Problems
[Free Registration/Login may be required to access all resource tools.] The video describes how to work backwards using addition and subtraction to solve for a specific value.
CK-12 Foundation
Ck 12: Elem Math: Addition Complete the Addition Sentence
[Free Registration/Login may be required to access all resource tools.] The video shows how to work backwards to solve a 3-digit addition problem. The video is followed by practice problems covering the topics in the video.
CK-12 Foundation
Ck 12: Elem Math: Adding and Subtracting With Parentheses Missing Number
[Free Registration/Login may be required to access all resource tools.] This is a video and practice problems finding the missing number of a multi-step addition and subtraction problem that has parentheses. The video models the process...
University of Cambridge
University of Cambridge: Nrich: Routes 1 and 5
Sharpen your logic and basic arithmetic skills while working on this challenge. Solution.
Purple Math
Purplemath: Finding Quadratics From Their Zeroes
Students often have difficulty "working backwards" from the solution of a problem to its original question. Finding a polynomial, given its roots, is an example of a "working backwards" problem. Here are several examples using different...
Annenberg Foundation
Annenberg Learner: Patterns in Mathematics: Mystery Operations
This interactive activity allows you to change an equation's numbers in an attempt to figure out what operations are being used to control the answers.
Alabama Learning Exchange
Alex: Getting Froggy Wih It
Students will solve problems using a number line. Students will work collaboratively to create a "Town" with the main street consisting of a number line diagram. They will practice counting forwards and backwards, measuring and...