Illustrative Mathematics
Shirt Sale
Everyone loves a good deal, and your mathematician's job is to calculate the original price when given the discount. A different type of problem than the traditional "find the percent change" has your learners working backwards to...
Curated OER
Equations and Inequalities Projects
Students compose equations and inequalities whose solutions are the integers 1-31 and utilize them to number one month of a calendar. They take notes on two ways to work backwards from a solution: by using the number and by setting x...
Education Development Center
Creating Data Sets from Statistical Measures
Explore the measures of central tendency through a challenging task. Given values for the mean, median, mode, and range, collaborative groups create a set of data that would produce those values. They then critique other answers and...
Curated OER
Bernardo and Sylvia Play a Game
This activity presents a game played by two learners whose solution is an exercise in creating and analyzing with algebraic inequalities.
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.
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.