Teachers who use problem solving as a focus of their mathematics teaching help students
develop and extend a repertoire of strategies and methods that they can apply when
solving various kinds of problems – instructional problems, routine problems, and nonroutine
problems. Students develop this repertoire over time, as their problem-solving
skills mature. By secondary school, students will have learned many problem-solving
strategies that they can flexibly use to investigate mathematical concepts or can apply
when faced with unfamiliar problem-solving situations