Source:; Wikimedia Commons |

This post was inspired, as always, by talking to a fellow teacher, in this case about the numeracy that kids need to navigate in the world.

I will begin with a confession: I am relatively innumerate, with regard to Imperial and US Customary units. Not coincidentally, I was born the year Canada went Metric.

If I am cooking a steak, and it's supposed to be 1" thick, I have no solid conceptual anchor for what that looks like, in my mind. I know I am a bit over 6 feet tall, but I only know I am 183 cm tall because my driver's license says. So, when my sons were born, they were around 9 lb, so I guess that made them about the weight of medium size turkeys, at that time. I never learned mental math tricks for converting between pounds and kilograms. When I travel to the United States, temperatures in Fahrenheit make no sense. Right, except on my house thermostat, on which I know 70 feels cold, if using air conditioning in the summer.

Home Depot is a strange world of things I barely know about. Don't even ask me about that. I know fractions well, but not fractions of inches in the screw section. Is a 2 by 4 really a 2 by 4? I hear not, but how would I know?

The sordid history of metrication in Canada is covered nicely in the Wikipedia article. Basically, it stalled, due to our historical relationship with the UK, and our current relationship with the United States. We are stuck in the middle, seemingly permanently.

Why does this matter?

In Ontario, there is no mention of Imperial units until grade 10, and then only in the Applied course:

#### -perform everyday conversions between the imperial system and the metric system (e.g., millilitres to cups, centimetres to inches) and within these systems (e.g., cubic metres to cubic centimetres, square feet to square yards), as necessary to solve problems involving measurement (Sample problem: A vertical post is to be supported by a wooden pole, secured on the ground at an angle of elevation of 60°, and reaching 3 m up the post from its base. If wood is sold by the foot, how many feet of wood are needed to make the pole?)

By this point, it's too late. Numeracy starts at birth. There is also an unbelievably patronizing aspect here: the Applied students are more likely to go into the trades, and therefore are the only ones who "need" to know Imperial units, while the students in the Academic stream march steadily into more abstract territory, with Algebra, and Calculus, as always, the pinnacle of K-12 mathematics education.

Meanwhile, the goal of the school system is to graduate educated, literate and numerate adults. Being caught between two systems of measurement is not doing our students any favours.