This video shows a quick activity, families (or teachers) can do at home (or school) to support understanding of teen numbers. I used what I had – buttons, paper, marker and a four year old. This activity is more appropriate for kindergarten age students or first grade students still developing their sense of teen numbers. It gets at the idea of ten being not only a group of ten ones, but that it could also be considered one ten, an important concept for children to grasp to understand place value. It moves from using concrete objects, to representing them on a ten frame and then using the number symbol for teen numbers. It also helps children see the “hidden” 10 in teen numbers, something not obvious since we say “teen” not “ten”.

Credit for the idea of this activity goes to Melissa Hedges and Beth Schefelker who facilitate the Numbers and Operations in Base Ten, K-2 module for the Brookhill Institute of Mathematics. They are amazing teachers and mathematics leaders!

**Here are a couple of items to note:**

- This activity requires that your child/student know how to count and read numbers to 20.
- After counting, it is important to ask, “So how many?” This indicates that your child/student understands an aspect of cardinality that the last number you say represents to total collection. If your child needs to recount the collection each time, this task might be too advanced. Working on basic counting and one-to-one correspondence would be more appropriate.
- If your child is an older kindergartener, a good question to ask about the group of 10 ones would be, “What else could we call this group?” The idea is to help your child think flexibly about 10 as a set or group. Ten can be considered 10 ones (that can be broken apart when regrouping in double digit subtraction) or ten can be 1 ten that can be thought of as a clump or group (so that 2 can represent 20 in the numeral 25).
- The steps of this activity are important. Children/students move from working with concrete objects (i.e. buttons) to representations (ten frames – adding a step where students match a ten frame to their button ten frame would be good) and then to the symbolic (using the numerals to represent the teen numbers). For children/students who have worked with or have understanding of number bonds, number trees or equations, ask the child to represent the activity with one of these abstract concepts as a concluding step.

The handmade ten frames are available for free as (nicer) PDFs on Teachers Pay Teachers. The place value cards are available there too but I had list them at a cost (too many pages). I’ve added a new page for downloads so you can find the place value cards right here for free!