It is very common for students to have difficulty with the numbers 11- 19. Their 
names do not follow a pattern and must be considered sight words/ numbers of 
mathematics. Teachers must ACTIVELY help students develop meaning for both the 
words and the corresponding numerals. 
There are many intervention strategies to help students make sense of the "teen numbers from 11-19."
www.mathwire.com has the following suggestions:
1. First, work on rote counting from 10-20.
- Identify the student's comfort zone: add 1-2 
numbers at a time to the 1-10 sequence until the student can reliably count on 
using the correct names.
- Sing songs and extend counting songs: for example, 
Ten Little Indians can be modified and extended to be 11 little, 
12 little, 13 little teddy bears (or dinosaurs or valentines, etc.). Singing is 
great reinforcement for many students and helps them acquire fluency with these 
extended numbers more easily than simply counting aloud.
- Who Has The Number?: Give students the large  demo-size cards (#10-20) and have them hold up the cards as you 
sing the song so that students hear and see the numbers. demo-size cards (#10-20) and have them hold up the cards as you 
sing the song so that students hear and see the numbers.
- Teen Line-up: distribute the large  demo-size cards (#10-20) and ask students to line up in the correct 
order. NOTE: numbers 10 and 20 of the teen demo cards are boxed in bright orange 
[see picture at left] to visually reinforce the notion that the teen numbers are 
between 10 and 20. Reinforce this notion often when 
working with the teen demo cards. demo-size cards (#10-20) and ask students to line up in the correct 
order. NOTE: numbers 10 and 20 of the teen demo cards are boxed in bright orange 
[see picture at left] to visually reinforce the notion that the teen numbers are 
between 10 and 20. Reinforce this notion often when 
working with the teen demo cards.
2. Learn to recognize the teen numbers.
- Matching Station: Provide many copies of the teen 
number cards for students to match to teen numbers in sequential order.
- Matching Sing-along: As students sing extended 
teen number songs, have students point to teen number cards to imprint written 
number with the oral name.
- Teen Line-Up: students shuffle number cards, then 
place them in sequential order. After this, students point to each number and 
name it.
- Teen Swiper: One student places the teen numbers 
in sequential order on the floor then removes a card while the other student has 
eyes closed. This student opens eyes and names the missing number. He/she must 
then locate that number in a second pile of all teen numbers and place it in the 
correct place. For this game, it is helpful to have two decks printed on 
different color paper, or in different color fonts for easy separation into two 
complete decks. 
3.  Next, attach meaning to the number.
- Four-handed Teens: Have student pairs represent 
teen numbers. One student holds up both hands to represent 10 fingers. The other 
student shows additional fingers to represent the teen number.
- Stamping sets: Give student number cards and have 
student stamp that many objects on the card.
- Teen Number Posters: Hang  number posters for numbers 11-20 on classroom walls. These posters 
include the base-ten representation of each number. Regularly include these in 
rote counting activities, counting 1-20 while pointing to the posters. Introduce 
the teen numbers as between 10 and 20. number posters for numbers 11-20 on classroom walls. These posters 
include the base-ten representation of each number. Regularly include these in 
rote counting activities, counting 1-20 while pointing to the posters. Introduce 
the teen numbers as between 10 and 20.
- Teen Number Mats: Provide number card mats for each 
number 11-19 and have students count aloud as they place counters on the mat. 
(Modification would be providing dots on which students place the counters as 
they count aloud.) NOTE: There is no effort to group materials or make tens at 
this stage. Students are simply attaching rote counting to one-to-one 
correspondence and the beginning of number recognition.
4.  Learn to model numbers to make sense of the number value and number sequence.
- Use of Base-Ten Blocks: This should follow lots of 
practice with non-grouped materials and students should use base-ten blocks and 
a  place-value mat concretely, 
writing only the answer to modeling the numbers to attach meaning to how many 
ones and how many tens they have. place-value mat concretely, 
writing only the answer to modeling the numbers to attach meaning to how many 
ones and how many tens they have.
- Pictorial Representation: Be sure to model for 
students how they can use simple lines and dots to represent the base-ten blocks 
to record their thinking. This semi-concrete step is often skipped when teachers 
go from concrete (base-ten blocks) to abstract (numbers on a page). Students who 
use this pictorial step have access to more powerful mathematical reasoning by 
using this intermediate step to think through problems beyond 
what they have learned.
- Overhead practice: after students have had lots 
of hands-on experience, use an overhead to present either the blocks alone or 
the number alone and ask students to quickly model the number on their  place-value mats, filling in the missing information. place-value mats, filling in the missing information.
 
 
I'm going to add my own activity at this point... learning to recognize that teen numbers are composed of "ten and a specific number of "more"... which helps to attach meaning to the number.  In addition,  the teen 10 frames cards also help students to see and interact with the model to make sense of the number value.
 
    Ten frames are an invaluable resources to visualize this concept of ten plus a specific number of more.
 
So I created a set of eye-catching snowmen demonstration ten + frame cards from 10-20 in both demonstration size and 4 on a page size , a set of expressions strips from 10 + 0 = through 10 + 10 =, and a set of equation cards in which the word for the teen is featured in both English and Spanish, i.e. 10 + 4 = fourteen,  10 + 4 = catorce.
 
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| 4 of the suggestion cards based on Debbie Diller's "I Can" cards | 
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| 10 frame card set with 8 suggested games 
 Deborah
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 This ten frame set  can be purchased at either my Teachers Pay Teachers store , or you can make your own cards using my pictured examples to help you.