Teen numbers in English are STRANGE. I mean, look at these weirdos in the first half of the numbers:
11 – eleven (not one teen)
12 – twelve (not two teen)
13 – thirteen (not three teen)
14 – fourteen
15– fifteen (not five teen)
16 – sixteen
17 – seventeen
18 – eighteen
19 – nineteen
When we start teaching these numbers to our youngest learners, we often take for granted the strangeness of the names of these numbers.We are used to the names and counting with them…we don’t even question or notice how strange they are. The first half of them don’t even follow a logical pattern! In addition, I often hear videos being played where the singer is saying “Teen numbers start with a 1!” Actually, teen numbers are written with a 1 first yes, but that one in the teen number does NOT have a value of “one”.
Teen numbers are the basis of place value. I still work with third graders who will see 10+6 and start counting on their fingers to figure it out! How they don’t know that shortcut always shocks me. I think somewhere we failed them in understanding the value of the 1 in the teen number.
Beginning to learn about place value for our early learners needs to include some key things. We have to spend a lot of time letting them play with the numbers, get comfortable with different representations of those numbers, including finding the ten that is hiding in the number. In many state standards teen numbers are expected to be thought of/written as a group of 10 and some more ones. YES, this is key! In the photo below you’ll see some of these various representations with fingers and numbers. In future posts, I’ll show some other representations and tools that work AWESOME.
In addition concrete tools should also be incorporated as much as possible! Here we are using units of one and ten to make it match the fingers. Very powerful for them to connect a tool from their body (fingers) to a more abstract tool (base ten blocks).
Never skimp on those teen numbers kindergarten teachers! Future grade levels depend on you to explore these concepts deeply with your students.