Kindergarten · Math · Parent guide

Teen Numbers as Ten Plus MoreK.NBT.A.1

Short answer. K.NBT.A.1 means your kindergartener learns that teen numbers are ten ones plus extras, like 18 = 10 + 8. What it looks like and easy ways to practice at home.

Grade: Kindergarten
Subject: Math
Framework: Common Core

Quick answer

What K.NBT.A.1 means in plain English

This is the first place value standard your child will ever meet. It asks her to see the numbers 11 through 19 as a group of ten plus some leftovers, so 14 is not just a word she recites but ten ones and 4 more. Teachers want kids to build these numbers with objects or drawings and write the matching equation, like 17 = 10 + 7.

Why parents see this skill

Why this matters

Every bit of multi-digit math coming in grades 1 and 2 rests on the idea that our number system bundles things into tens. A child who truly sees 16 as 10 + 6 will later add 26 + 10 in her head instead of counting on her fingers.

For reference

The official wording

CCSS.MATH.CONTENT.K.NBT.A.1

Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.

Official Common Core source

See it, then try it

How this skill can look at home

You do not need a lesson plan. Look for these signs in ordinary play, reading, and conversation, then choose one short activity.

What you may notice

Your child can grab 13 cereal pieces, push 10 into one pile, and tell you there are 3 extra.
She starts saying things like 'fifteen is ten and five' without being prompted.
Your child can finish equations like 12 = 10 + __ using blocks, buttons, or a drawing.
She can hear a teen number, say 19, and build it as a full ten-frame plus 9 more.

Simple ways to practice

01
Egg Carton Tens
Cut an egg carton down to 10 cups. Give your child a teen number of dry beans, have her fill the carton first, then count what is left over. Ask, 'So 14 is ten and how many more?' Repeat with 2 or 3 different teen numbers.
02
Ten and Some Snack
At snack time, count out a teen number of crackers together. Line up 10 on a napkin and set the rest beside it. Have her say the equation out loud, '16 equals 10 plus 6,' before she gets to eat them.
03
Teen Number Draw
Say a number between 11 and 19. Your child draws a stick of 10 circles in a row, then the extra circles below it, and writes the equation underneath, like 18 = 10 + 8. Two or three rounds is plenty for one sitting.

Choose what helps today

Start with the domain guide for context, use the learning library when a concept needs explaining, or print a page when your child is ready to practice.

Frequently asked questions

My kindergartener can count to 19 but cannot break 14 into 10 + 4. Is she behind?

Not at all. Reciting the counting sequence and understanding place value are two different skills, and this one usually clicks in the second half of the kindergarten year. Keep building teen numbers with real objects, because seeing the pile of ten makes the idea concrete in a way flashcards cannot.

How do schools test K.NBT.A.1?

Usually with hands-on tasks, not written exams. A teacher might give your child 15 counters and ask her to make a group of ten, or show a ten-frame with extras and ask what number it shows. Some classrooms also ask kids to complete simple equations like 13 = 10 + __.

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