Tag Archives: and


How many dalmatians were in that movie again?

It was one-hundred-and-one, right?

Have I angered you yet? If you teach math, I probably have.

See, we math teachers are precise people. We like things to be just right. Part of being just right is using language correctly. In English number language, and is reserved for separating the whole number part of a number from the fractional part.

One and one-half

One and seven tenths

That sort of thing.

So when we hear one hundred and one, we freak out.

But separating the whole number part from the fractional part? That’s just one perspective. Sure, it’s the grammatically correct one.

But here’s the thing about grammar rules…they are arbitrary. Totally and completely arbitrary. Name a grammar rule and there’s a language somewhere that violates it completely.

Yet we English-speaking math teachers act as though the use of and were a signifier of mathematical understanding or competence. Which it is not.

Here’s another interpretation of and in English number language. Maybe and signifies a change of unit. In one and seven tenths, one is counting the original unit, seven is counting tenths. The and helps the listener to follow along; it signifies this shift.

In that case, one hundred and one is the same way. The first one counts a unit-hundreds. The second one (following the and) counts a different unit (which, awkwardly, we call either ones or units).

If I’m right about this, then you will have heard native speakers of English say something such as,

Three hundred and four thousand and twelve.

Three hundred and four counts thousands. Twelve counts ones. Then within the three hundred and four part, there are two different units also. Hence the and.

If I’m right, then you will probably not have heard native speakers of English say something such as,

Thirty and four.

Both of those words count the same units.

So I say let’s give up on this little obsession we have about and. Let’s not let it get in the way of effective, efficient communication in mathematics classrooms.

Let’s save our wrath for this:

Three point twelve.