Number sense is more of a way of teaching than a topic to be taught." (Van de Walle and Watkins, 1993)  The NCTM Standards state that "children must understand numbers if they are to make sense of the ways numbers are used in their everyday world" (NCTM, 1989).  In the document entitled Everyday Counts put out by the National Research Council, the major objective listed for elementary school mathematics is to ensure that students develop number sense (NRC, 1989).  The document goes on to say that number sense is comparable to common sense in that it produces useful results (NRC, 1989).  Number sense will take students beyond the "narrow concern for school-certified algorithms for arithmetic" (NRC, 1989).  School children also need to know how to use math in the real world (NRC, 1989).  For example, students need to know how to make change, measure quantities, plan schedules, etc.  Essentially, number sense helps students apply math to what they are expected to do in the real world.

Number sense not only helps students relate math to the real world, it helps them to build natural insights and makes them see that math makes sense (Howden, 1989).  Once students begin to see that math makes sense, they gain confidence in their ability to do math (Howden, 1989).

The NCTM Curriculum and Evaluation Standards (1989) for number sense calls for students to "understand our numeration system by relating, grouping, and place value concepts."  It also states:  "Children with good number sense have (1) well-understood number meanings, (2) have developed multiple relationships among numbers, (3) recognize the relative magnitudes of numbers, (4) know the relative effect of operating on numbers, and (5) develop referents for measures of common objects and situations in their environments." (Hatfield, et al., 1997).

Children are not born with number sense.  Teachers must teach number sense.  How does a teacher go about teaching number sense?  Essentially, teachers must immerse students in experiences in which they manipulate physical objects.  Later, students should be encouraged to talk about what they are thinking.