We have been taking a closer look at the numbers 11-19 and diving into what makes them to different than the rest of our numbers. Let's start with their names; confusing. There is no other way to describe it. When I learned to count in Japanese (ju ichi- ten one, ju ni- ten two), I thought to myself "this makes a whole lot more sense." Our number system is grounded in the concept of base ten. We need to start teaching kids the value of "10" right from the start. The number 1 in 12 does not stand for 1 single object, but rather a whole group of 10! Ten frames work really well for this! We want kids to see that the group of 10 right away and then see how many are left over. We are playing a lot of games that use the ten frame cards to help identify the teen numbers. Students are able to then quickly see that the numbers are made up of one group of 10 and a certain number left over. |
Students also need to be able to show this concept using a variety of manipulatives. Counters, seeds, connecting cubes, and actual base 10 blocks are all ways that they can be showing the value of teen numbers. This is a big concept that can be then applied to numbers higher than the teens. One of the best ways for you to practice this at home is to count large groups of objects together (30-100). Discover different strategies for grouping the objects so that it is easier to keep track of the number as you go. Counting 100 objects by 1's is nearly difficult to do without having to start over a bunch of times. 100 objects grouped in 10 groups of 10 is simple, 10, 20, 30, 40...Students will discover this method of grouping by tens naturally. Then start adding in the ones, like 37 (3 groups of 10 and 7 left over).