Math Expressions Kindergarten, Unit 3: Teen Numbers and Generative Building
In this unit, your child learns that teen numbers are a ten and some more ones, such as 14 = 10 + 4, and keeps counting higher, by ones and by tens, toward 100. Just as 6 to 10 were built from 5 and some more in the last unit, the teens are built from 10. Next come number partners, addition, and subtraction.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 3?
- Building numbers 11 to 19 from ten ones and some more ones, and writing equations such as 14 = 10 + 4. Learn more: Teen numbers as ten and some more
- Counting aloud to 100 by ones and by tens, and hearing the pattern that repeats in each set of ten. Learn more about counting to 100 by ones: Counting to 100 by ones · Learn more about counting to 100 by tens
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
What do 10 and 1 make?
- 10
- 11
- 12
How you can help
- Count 10 crackers onto a napkin, then add a few more on the side. Ask your child to name the teen number and say it as ten and some more.
- Count by ones together on a walk or ride, and celebrate each new ten with a high five: 10, 20, 30, and on.
- Write a teen number like 18 and show it with fingers together: you hold up all 10 of yours, and your child holds up 8.
Where kids can get stuck
- Thinking the 1 in 14 means one thing, so they show 14 with 1 block and 4 more.
- Getting stuck after 39 or 49, not sure which ten comes next.
- Losing count while making the ten, so the group ends up with 9 or 11.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- teen number
- A number from 11 to 19, made of ten and some more ones.
- ten ones
- Ten single things, which together make one ten.
- ones
- Single things, counted one at a time.
- equation
- A number sentence with an equal sign, like 3 + 2 = 5.
- count by tens
- Saying 10, 20, 30, and on, adding one group of ten each time.
- hundred
- The number 100, which is ten tens.
Want to help your child master teen numbers and tens?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
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Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Math Expressions Kindergarten Unit 3 cover?
Math Expressions Kindergarten Unit 3 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.