What Number Sense Means

Parents, there is a lot of discussion in education about what being "mathematically literate" and “developing number sense" means.  I came across this activity from Cathy Fosnot, who is a Professor or Education in the USA and a Director of Mathematics in the City, a national centre for professional development at the college.  Cathy Fosnot worked directly with Royal Oak teachers last year and her materials are being used again this year.

One of her books begins with this:

“Try an experiment.  Calculate 3996+4246.  Don’t read on until you have an answer.  If you are like most people who are products of the American School system, you probably got a pencil and paper, wrote the numbers in columns, added the units and regrouped, then added each remaining column, right to left.  If you didn’t, congratulations!  You probably have number sense.  What would someone with good number sense do?  What would a mathematician do?  Both would look at the numbers first and decide on a strategy.”  [Then she goes on to a lengthy discussion about what we'd like students to be able to do with that question.]

I love this example to illustrate one of our goals with our young mathematicians – and that is to develop their ability to be flexible and efficient with numbers.  Happy adding and subtracting!