Teen Numbers: Ten and Some Ones

Teen numbers mix a familiar ten with a variable set of ones, a concept that challenges young learners to shift from seeing numbers as single units to understanding them as composed groups. Hands-on activities let students build, manipulate, and visually separate the ten from the ones, which turns an abstract idea into something they can touch and see.

• Kindergarten
• Mathematics
• 3 activities
• 15 min–30 min

Learning Objectives

1. Demonstrate that a teen number is composed of one ten and some ones using manipulatives.
2. Analyze the written form of a teen number to identify the digit representing the group of ten and the digit representing the ones.
3. Explain how anchoring to the number 10 helps in composing and decomposing teen numbers.
4. Construct a representation of a teen number showing the group of ten and the individual ones.

Think-Pair-Share

⏱ 15 min·Pairs

Think-Pair-Share: Build It Two Ways

Give each student 15 linking cubes. First ask them to show 15 any way they choose. Then ask: 'Can you show 15 as a group of ten and some ones?' Partners compare their structures and explain why both arrangements still show 15. Discuss how breaking it into a group of ten reveals the structure.

Prepare & details

How does the number 10 help us understand numbers like 13 or 17?

Facilitation Tip: During Think-Pair-Share: Build It Two Ways, circulate and listen for students who describe the ten-group with language like ‘a stack’ or ‘a bundle’ rather than just ‘a one.’

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Stations Rotation

⏱ 30 min·Small Groups

Stations Rotation: Teen Number Lab

Stations include: bundle 10 craft sticks and add loose ones for a given teen number; fill a ten-frame completely and show extra ones beside it; and match a written teen numeral to a ten-and-ones drawing. Rotate every 8 minutes. Students record the equation (14 = 10 + 4) at each station.

Prepare & details

Construct a model to show that 14 is a group of ten and four ones.

Facilitation Tip: In Teen Number Lab, insist on the same start for every station: students first build the full teen number with a ten-stick and loose cubes before writing any equation.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Gallery Walk

⏱ 30 min·Small Groups

Gallery Walk: Prove It Posters

Assign each small group a teen number. Groups create a poster showing: a bundle of ten plus loose ones, a filled ten-frame with extras, and the written equation (e.g., 14 = 10 + 4). Post around the room for a gallery walk where other groups leave one sticky-note observation on each poster.

Prepare & details

Analyze why teen numbers are written with a '1' in the tens place.

Facilitation Tip: At Prove It Posters, ask students to hold up their ten-bundle when they explain the ‘1’ in their poster number to make the connection concrete.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Teaching This Topic

Teach teen numbers by keeping the routine identical each time so students notice the pattern instead of treating each number as brand new. Use two-color tools so the ten-group stands out visually, and always bridge from the physical build to the written equation by pointing to each part while students hold the objects. Avoid rushing to symbolic notation before students can consistently explain the ten and the ones in their own words.

What to Expect

Students will confidently build teen numbers using a group of ten and some extra ones. They will explain the structure of each teen number both verbally and in writing, showing they see the ‘1’ as one group of ten and the second digit as the extra ones. By the end of these activities, they will write and read equations like 15 = 10 + 5 with clarity.

Watch Out for These Misconceptions

Common Misconception

During Think-Pair-Share: Build It Two Ways, watch for students who build the ten but do not point to the digit ‘1’ when naming the group of ten.

What to Teach Instead

Prompt them to hold the ten-bundle while saying ‘one ten’ and then write the digit ‘1’ next to it on their paper, linking the bundle to the symbol.

Common Misconception

During Teen Number Lab, watch for students who treat each teen number as a separate fact rather than noticing the consistent ten plus some ones structure.

What to Teach Instead

Pause the station and have the whole group build 12, then 15, then 18 in sequence, asking what is the same and what is different so they see the repeated pattern.

Common Misconception

During Prove It Posters, watch for students who write the equation correctly but cannot explain what the ‘1’ represents when asked.

What to Teach Instead

Have them pick up their ten-bundle while saying ‘This is the ten the 1 stands for,’ then place it next to the ‘1’ in their poster to make the connection visible.

Assessment Ideas

Exit Ticket

After Think-Pair-Share: Build It Two Ways, give students a card with a teen number. Ask them to draw a picture showing one group of ten and the extra ones, and to write the matching equation 10 + __ = __ below it.

Quick Check

During Teen Number Lab, as students finish a station, show them a collection of 10 blocks and 7 loose blocks. Ask, ‘How many blocks in all? How many groups of ten do you have? How many ones?’ Listen for answers that match the physical count.

Discussion Prompt

After Prove It Posters are displayed, hold a whole-group discussion. Show the numeral ‘14’ and ask, ‘What does the 1 tell us? What does the 4 tell us? How do you know 14 is made of ten and four more?’ Call on students to point to the matching parts on their posters.

Extensions & Scaffolding

• Challenge early finishers to create a teen-number booklet where they draw each number as a ten-stick and ones below and write the matching equation.
• Scaffolding for struggling students: Provide a ten-stick and a set of pre-counted loose cubes so they must place exactly the right number of ones to match the numeral.
• Deeper exploration: Invite students to compare two teen numbers (e.g., 13 and 17) and explain which has more ones and how they know.

Key Vocabulary

teen number	Numbers from 11 through 19. These numbers are made by combining a group of ten with some additional ones.
group of ten	A collection of 10 items, considered as a single unit. For teen numbers, this is the first part of the number.
ones	Individual items that are added to a group of ten to make a teen number. These are the single units.
place value	The value of a digit based on its position in a number. In teen numbers, the '1' is in the tens place, meaning it represents one group of ten.