Heuristics are general strategies through which a problem solver moves towards a solution as in Polya’s (1971) classic How to Solve It where he prescribed the following 4-phased process.
What is the problem asking you to do? What are we trying to find out? Can we restate the problem?
What do we know? What do we need to do to solve the problem? Do we need more information? Is there a hidden question? What strategies are useful?
Carry out the plan. Apply mathematical skills, concepts and strategies.
Compare with the original question. Does it make sense? Should we revise our plan to meet all the conditions?
Some common heuristics include the following:
1. Model method (Part-whole, comparison, before-after)
2. Draw a diagram or picture
3. Make a systematic list
4. Look for patterns
5. Guess and check
6. Simplify the problem
7. Work backwards
Reference: Foong, P.Y. (2008). Problem Solving in Mathematics. In P.Y. Lee & N. H. Lee (Eds.), Teaching Primary School Mathematics: A Resource Book (pp. 62). Singapore: McGraw-Hill Education.