Number Sense Blog

Add 17 + 18 + 19. Do it quick! If you reached for a scratch sheet to get to the solution of 54, you didn't do it wrong, but here's a different way to think about this question:First, round each number to the nearest 10 (20 in this case), and add t...

I have often heard students coming out of a class saying, "That stuff doesn't make sense!" This is because many students have not developed a good general sense of the mathematical subject matter that is presented at school. Students are not provi...