Quite frankly, until you start doing algebra and then calculus, which generally starts at around grade 7 or so, what kids are doing in elementary school is the most basic arithmetic. Adding, subtracting, learning about multiplication and division (more advanced obviously) and finally, doing these things with fractions. 

As others have pointed out on this board, pretty well all of us who've gone through the Canadian school system have learned this stuff.  Some few people (and it is a minority still) may have learning disabilities that make it difficult for them to grasp the abstraction of numbers.  But most of us don't . I'm not a teacher and have showed kids how to do these basic things.

So I agree with this author - the new curriculum is uselessly challenging both the kids and their teachers.   I would suggest that this be dropped,  and that students with special needs have special instruction, and the rest just do their numbers. And learn not to be scared of basic arithmetic.