Earlier today we went to Petersham Nurseries for a slice of cake and a tea. Lovely, as usual.
Also, for some reasons we started discussing how wide a pick up truck is. I said may be something like 2 metres, but wasn't sure. Also, I said we could compare my height to the width of parked cars to get a rough idea (although there was no pick up parked around).
Since I didn't want to lie on the dusty ground, Marta said that a person's height is more or less the same as their arm-to-arm length and that I could just stand in front of a parked car with my arms spread out.
I have never heard of this, so when we got home we did a little experiment to see if it worked. Marta's parents are visiting us, so we have a veeeery small sample of size 4 to go about. As it turned out, this worked pretty well and the arm-to-arm length was basically the same as the height (up to a couple of centimetres) in each of the 4 paired measurements (one arm-to-arm and one height for each of us).
May be I'll use this in one of my classes...