Teaching estimation and reasonableness of results

The National Council of Supervisors of Mathematics' Position Statement on Basic Mathematical Skills (1977) speaks to the importance of the two key ideas, “Alertness to the Reasonableness of Results” and “Etimation and Approximation.” In particular, the paper notes that these skills, although always important, have become even more critical in a world of calculators and computers. It is often necessary to assess a machine-produced result in terms of the reasonableness of the result when one considers the numbers involved or physical reality