Students' acquisition of higher-order thinking skills has long been a goal of mathematics educators. The National Council of Teachers of Mathematic (1980). in recommending that “problem solving be the focus of school mathematics in the 1980s.” noted that students must learn to “formulate key questions, analyze and conceptualize problems, define the problem and the goal, discover patterns and similarities, seek out appropriate data, experiment, transfer skills and strategies to new situations, and draw on background knowledge to apply mathematics” [emphasis added]. It is imperative that the reource teachers use to teach tho e skill be equal to the challenge of this goal.