Are You Five Ten or One Seventy-Five?

I was walking along the first floor hallway yesterday and was just about to get into the elevator when I heard one of our international students ask someone from the TESOL office how tall he was. "Five ten" was the reply to which the international students responded "Five, ten? What is this five, ten?" He was smiling and clearly was amused by the use of two numbers to convey someone's height. They had apparently been in conversation for several minutes as the TESOL employee began to elaborate by saying "five feet and ten inches" to which the international student replied "what is an inch and what is a foot?". I wanted to ask the international student how tall he was; anticipating a reply of  175 or 180 or so but the elevator arrived and I had to go and besides, I didn't want to intrude on what was a wonderful internationally defined conversation.

The use of the implicit referent is commonplace throughout our culture. Prices are usually given in the form of three ninety-nine or two twenty-five. We talk about the size of a motorcycle as a seven fifty or a twelve hundred and snowboarders and skateboarders routinely do one-eighties and three sixties. The time is always given without a referent and sportscasters  could not survive if they had to give the referent for every number they used. An ERA of point three five eight, hitting three forty, winning five to three and declaring at five hundred twenty six for six.

This is all well and fine when you are a native to the culture but when you are not it can cause considerable difficulties. For example, in the above examples what does "declaring for five hundred twenty six for six" mean?  And if you had to fill your car with gas in Montreal about how many litres would it take? 

When we teach math to English Learners we must remember to a) make the referents explicit and b) give students a sense of the size of each referent so they can understand the significance of the measurements they are using.