Ask the teacher: Is 11 a teen number?

Here’s a great kindergarten math question that I posed to the awesome kindergarten teachers on facebook. “Is 11 a teen number?” Here is your answer straight from the source – what real kindergarten teachers have to say about 11 being a teen number.

Plus, I’ll weigh in on the subject too with a pictured explanation.

Teachers were polled: Is 11 a teen number?

When asked, the overwhelming majority of kindergarten teachers said yes.

And yes – as the people who teach these things to five and six year olds – we are in agreement with our kinders that these irregularly named numbers indeed should have been named oneteen, twoteen and threeteen… {wink}

What the teachers said

Here are examples of what other kindergarten teachers had to say:

Yes, teen family is numbers 10-19. – Diana B.

In the Kindergarten world, the answer is yes. It makes sense to go with teens starting with 10-19 on the hundreds chart when you work with numbers to 100. You just go with a few having oddball names 11 and 12. In the growing up teenager world…no, it’s technically 13-19. – Jeanne S.

Bahaha, I just had this conversation with my Kinders yesterday . I told them that even though you don’t say eleven-teen or twelve-teen they are still teen numbers because (like the song says) they start with a 1. Thank you Harry Kindergarten, lol! – Maureen D.

Yes, 1 group tens and some ones. Both #’s require you bundle and unbundle to regroup when adding and subtracting. If not a teen then what? – Karri C.

Yes, however I tell my students people aren’t teenagers until they are 13 – Jennifer L.

A side note: I agree with my peers that mathematically speaking 11 is a teen number – but if you’re categorizing the ages of children – then 11 is a pre-teen number. There is a big difference in the maturity and development that happens in those pre-teen years.

Now, here’s a little bit more about why 11 is indeed a teen number when we’re talking all things math.

Why 11 is a Teen Number

It’s all based on our numbering system (which is called base ten). Our numbers become grouped based on sets/groups of ten. That means every time you hit a new grouping of ten objects, the number range changes in name.

If a number has one group of ten and additional ones (single objects), then I believe it qualifies as a teen number.

Let’s look at how this works by starting out with the number 9.

Nine is nine single objects.

It’s not a teen number since it lacks a group of ten.

When you add one more, you make a complete group of 10.

10 is one group and zero single objects. The 1 in 10 represents the group and the 0 represents the zero objects.

Ten is not a teen number even though it has one group of ten. It lacks the additional ones.

When you add one more, you have 11.

Let me model how to use the ten frame and a crayon to show how to decompose the numbers into tens and ones.

11 is one group of ten and one single object. The first 1 in 11 represents the group of ten and the second 1 represents the 1 single object.

It is the first teen number since it has just one group of ten and additional ones.

To hit this point home, lets take a number that says “teen” in the name. Let’s decompose 17 into tens and ones.

Is 11 a teen number - composing and decomposing

17 is one group of ten and seven single objects. The 1 in 17 represents the group of ten and the 7 represents the 7 single objects.

It plainly says “teen” but qualifies since it has one group of ten and additional ones.

Here is a famous video (in the world of kindergarten anyway) that teaches how the teens all start with a 1.

Catchy, isn’t it?

I literally didn’t get this at all growing up. I was taught using tally marks and bundles of straws during calendar time. Yeah, that didn’t work.

Only once I started teaching the standard of composing and decomposing numbers 11-19 to my own classes of kindergartners using the ten frame did I understand the huge importance this concept plays in the world of understanding numbers.

creating ten frame manipulatives - KindergartenWorks

I wish I had been taught this using a tool like the ten frame growing up.

It’s so powerful that I made my own ten frame manipulatives to use with my class and we used them all the time!

So, yes – 11 is a teen number.

So are 12, 13, 14, 15, 16, 17, 18 and 19.

Here’s a lesson example to teach how to compose and decompose teen numbers. It can even be used with accelerated kindergartners or even first graders with numbers to 99.