Fun and Hands-On Number Sense Activities to Boost Kids’ Math Skills

Math tips and strategies for building number sense to 20 in Kindergarten and first grade: This blog post includes an extensive list of number sense activities and resources are included: books, materials, math manipulatives, and FREE activities!

Building Number Sense to 20

Here are the math tips and strategies you need to build number sense to 20. You will have everything you need to quickly implement and bring a wealth of number sense activities, games, and centers into your classroom or home.

The activities, books, and resource suggestions (including a FREE one) cover many number sense concepts and are perfect for Kindergarten and first grade. Plus, find valuable number sense materials, manipulative suggestions, and freebies you can access today!

Why is Building Number Sense Important?

Children need opportunities to learn and experience numbers. Essential concepts include counting, identifying numbers, and understanding quantity. Repeated experiences build understanding and fluency with numbers, helping children expand their knowledge and learn new ideas. A strong number sense is vital for understanding more complex math topics later. Once they’ve mastered numbers to 10, they’re ready for these activities.

The activities below have worked well. Use them as described or adapt them to your own needs. Be flexible. Have conversations about numbers and encourage questions. When you can order, count, match, or describe with a child, go for it! Children benefit from seeing numbers in natural, fluid ways.

Make time for fun and engaging number activities daily and watch fluency develop.

Number Sense Concepts & Activities

Build Number Sense Through Counting

Count with children every day. Repeated oral counting helps them hear what numbers sound like and to learn their order. Using math manipulatives, like counting chips, can help build a connection to verbal counting and counting objects. This one-to-one correspondence when counting is an essential skill that needs frequent practice.

Activities

• Play number games with counting. Count aloud as a class, starting at 1 and building to higher numbers.
• Sit with a partner or in a circle and take turns counting by 1s.
• As counting develops, teach number patterns and counting by 2s, 5s, and 10s.
• Use a number chart or hundreds chart to see what numbers look like visually. Point to each number as it is said.
• Encourage kids to practice one-to-one counting with small objects. Set up small groups of objects in a center for them to count. Use a ten frame to help organize objects.
• Provide number cards (like those seen below) for kids to represent with counting chips.

Teacher Tip

Mix up how students practice counting so they don’t rely only on starting at 1. Once students are comfortable, ask them to start counting from a given number, such as 6 or 13, and continue to 20. You can also pause during counting and ask, “What number comes next?” to check whether students understand the sequence rather than simply reciting it from memory.

Differentiate

• Intervention: Use a number line or number chart as students count and have them touch each number as they say it. Keep practice to smaller ranges, such as 1–10, before building toward 20.
• On-Level: Have students count forward and backward within 20 and practice starting from different numbers.
• Enrichment: Challenge students to count forward from any number to 20 or count backward from 20. Introduce skip-counting by 2s, 5s, and 10s as students are ready.

Quick Formative Assessment

During a counting routine, choose a number between 1 and 20 and ask students what comes before and after it. Listen for students who skip numbers, repeat numbers, or rely heavily on the number chart. You can also have students count a small group of objects and then tell you how many they counted without recounting.

Build Number Sense by Matching Numbers to Quantities

Provide materials for kids to count and connect with objects and numbers in small groups. This encourages children to see that numbers are more than words and builds number recognition. Teach children that numbers have many representations, such as dots (subitizing), fingers, counters, numerals, objects, ten frames, etc.

Activities

• Match two different types of objects together, such as five counting bears and a domino that shows five dots.
• Use links to create a number chain for a number.
• Work up to showing quantity with more than two types of objects (as seen in the photo).
• Have many different items available for activities, such as dice, dominoes, number magnets, bears, counting chips, cubes, and number cards.

• Match number cards from a card deck or game of Uno with dots on dominoes. Find every number combination on the dominoes.

• Complete number puzzles with different number representations on each piece help kids see that numbers can be modeled in many ways. The number puzzles to 20 are available as a FREE download below.

• Encourage one-to-one counting with clip cards. Kids count groups of objects and clip the numeral that matches the correct quantity.
• Ten frames are great for organizing numbers for easy counting. Matching numeral cards with ten-frame representations is simple yet effective for building number identification skills and connecting quantity with numbers.

Teacher Tip

Encourage students to represent the same number in several ways. For example, if the numeral is 14, students might build 14 with cubes, show 14 on a ten frame, hold up 10 fingers and 4 more, and find a domino or dot card that represents 14. Discuss how each representation shows the same quantity to help students develop flexible number sense.

Differentiate

• Intervention: Start with numbers 1–10 and use concrete objects that students can touch and move as they count. Pair a numeral with one quantity at a time before asking students to match several representations.
• On-Level: Have students match numerals to quantities using different representations, including ten frames, fingers, dots, and manipulatives, within 20.
• Enrichment: Ask students to find multiple ways to represent the same number and explain how they know each representation shows the same quantity. Challenge them to represent teen numbers using a group of 10 and some extra ones.

Quick Formative Assessment

Show students a numeral between 11 and 20 and ask them to build or draw the quantity without counting one object at a time. Ask, “How do you know you made 16?” Listen for students who can connect the numeral to a group of 10 and additional ones.

Build Number Sense with Number of the Day

When kids repeatedly see numbers in many ways at once, their number sense develops. Pick a number for the day, starting at one, and dissect it during your math block.

Activities

• Learn about a specific number for each day you have been at school. Teach and dissect that number during calendar time. Represent that number on a number line, count to that number, show that number with straws or cubes, etc.
• Use a number-of-the-day poster or anchor chart to break numbers down. Create your number-of-the-day poster with the FREE poster templates.
• Encourage kids to participate and show their understanding on paper or mini whiteboards. Ask questions like “How do we show 5 with tally marks?” and allow them time to try independently. This makes an excellent fluency-building warm-up to math lessons.
• Read more tips on starting a number of the day routine in your classroom.

Teacher Tip

Use the number of the day to connect representations rather than treating each part as a separate task. For example, for 14, ask students to build 14 cubes, show it on a ten frame, write the numeral, and explain that 14 is made of 10 and 4 more. Revisit the same number throughout the day to give students repeated opportunities to see and describe it in different ways.

Differentiate

• Intervention: Focus on one or two representations at a time and use manipulatives, ten frames, and a number line to support students. Start with numbers within 10 before moving into teen numbers.
• On-Level: Have students represent the number of the day in several ways, including a numeral, quantity, ten frame, and number bond.
• Enrichment: Challenge students to find multiple ways to compose and decompose the number. For a number like 16, students might show 10 + 6, 8 + 8, or 12 + 4 and explain how each combination makes 16.

Quick Formative Assessment

Choose one representation and leave it blank on the number-of-the-day chart. Ask students to complete it independently on a mini whiteboard. For teen numbers, you might show a ten frame with 10 filled spaces and ask, “How many more do we need to make 17?” This quickly shows whether students understand the quantity and the relationship between 10 and the extra ones.

Build Number Sense by Ordering Numbers

Give kids opportunities to order numbers. While they put numbers or objects with numbers on them in the correct order, they count and build number sense.

Activities

• Provide opportunities to use a number line and a chart that puts numbers in order for us.
• Give sets of numbers to order correctly by finding them on the number line.
• Cover different numbers on a number chart with sticky notes and ask kids for the missing numbers.
• Build Lego stacks by putting the pieces together in an order written on the blocks.
• Work with a partner to order number cards from 0 to 20. Then, create a number caterpillar like the one below.

• Number puzzles are a fun way to order numbers. Put the strips in the correct order to reveal a picture.
• Puzzles are simple and easy to create. Take an old puzzle and write numbers on the back of each piece.
• Grab a piece of paper and write numbers in rows. Then, cut out pieces randomly and trade with a partner. Finally, put the puzzle back together again for practice.
• Complete a number-order maze starting at 0. You can reuse this activity by putting it in a pocket protector.

Teacher Tip

Ask students to explain how they know where a number belongs, rather than simply placing the cards in order. Encourage them to use the language “before,” “after,” and “between.” For example, ask, “Where would 15 go if we already have 13 and 17? How do you know?” This helps students connect number order to their position on a number line.

Differentiate

• Intervention: Begin with a smaller set of numbers, such as 1–10, and provide a number line students can reference. Gradually add teen numbers as their confidence grows.
• On-Level: Have students independently order mixed-up number cards from 0–20 and identify numbers that come before, after, or between others.
• Enrichment: Give students a partially completed sequence with missing numbers and ask them to determine what belongs in each space. Challenge them to create their own sequence for a partner to solve.

Quick Formative Assessment

Give each student three number cards, including a teen number, and ask them to put the numbers in order. Then ask, “Which number is in the middle? How do you know?” This quickly reveals whether students understand number order or are relying on memorized sequences.

Build Number Sense with Place Value Activities

Start teaching kids about place value by helping them see ten in many ways. Move on to illustrating numbers with base ten blocks.

Activities

• Practice making groups of ten things. Group straws, beans, counters, or any small objects.
• Teach counting by 10s to count groups. Extend to teaching groups first and then singles.
• Make groups of ten to get to the 100th day.
• Show and examine a tens block and a ones block. Discuss that a tens block has ten ones put together.
• Represent the number of tens and ones on place value mats (see below). Ask questions like “How many are there?” or “How many groups of ten?” Ensure they understand what each number within the number stands for (e.g., 1 in 18 is a ten, not a one).

• Use base ten blocks to represent numbers. Do plenty of examples where kids must use and count blocks. Use a chart to help count the blocks.
• Say, “Show (or draw) me 14 with place value blocks!”
• There are many ways to represent a number: expanded form, standard form, word form, numeral, etc. Worksheets like the one below can help build this connection.

Teacher Tip

Make the connection between a group of 10 and the number 10 explicit before moving into teen numbers. When students build 14, for example, have them make one group of 10 and 4 ones. Say, “Fourteen is one ten and four ones,” and then have students take the group apart to show that 14 can be decomposed into 10 + 4. Repeatedly connecting the concrete materials to the written numeral helps students understand what each digit represents.

Differentiate

• Intervention: Give students a ten frame or place value mat and have them physically build teen numbers with one group of 10 and individual counters. Focus on numbers 11–15 before moving through the rest of the teen numbers.
• On-Level: Have students build, draw, and write teen numbers using tens and ones. Ask them to compose and decompose numbers, such as showing 17 as 1 ten and 7 ones or 10 + 7.
• Enrichment: Challenge students to find different ways to decompose numbers within 20. For example, ask, “How many ways can you make 18?” Students might show 10 + 8, 9 + 9, or 12 + 6 and explain their thinking.

Quick Formative Assessment

Give students a numeral such as 13, 16, or 19 and ask them to build it with manipulatives. Then ask, “How many tens? How many ones?” and “What does the 1 in 16 mean?” This quickly shows whether students understand that the 1 represents one group of ten, not one single object.

Connect Composing and Decomposing: Give students opportunities to build a teen number, break it apart, and put it back together. For example, students can build 15 with one tens block and five ones, separate the blocks, and record 10 + 5 = 15. Continue reversing the process by giving students 10 and some ones and asking them to compose the number. These hands-on experiences help students see that teen numbers are made from one group of ten and additional ones.

Reading and Writing Numbers

Numbers constantly surround kids in their environment. They quickly learn to recognize numerals 0 to 9 through different experiences. Keep encouraging this familiarity by putting numbers on the wall. Posters, number lines, and calendars are helpful tools. Soon enough, they’ll be working with numbers to 100.

Activities

• Build numbers with playdough in a math center. Even something as simple as this playdough numbers activity here.
• Print numbers from 0 to 9 daily in different ways – in booklets, on whiteboards during math lessons, etc.
• Draw numbers on paper and give students do-a-dot markers or bingo dabbers to dot numbers.

• Trace numbers frequently and repeatedly to build coordination and correct form. The mini-book below encourages this, as well as locating numbers.

• Encourage correct number formation by teaching it explicitly. The posters (seen below) are helpful tools to use and post on the wall for students to reference during math mini-lessons.
• Catchy number poems help students visualize and remember number formation. Use your whole body to take action or draw in the air.

Teacher Tip

Give students frequent opportunities to read and write teen numbers in meaningful contexts, not just practice them on worksheets. Point out numbers they encounter throughout the day, such as page numbers, classroom labels, dates, and calendar numbers. When students write a teen number, have them say it aloud as they write it to strengthen the connection between the spoken number and its written form.

Differentiate

• Intervention: Focus on a few numbers at a time and provide visual models, tracing opportunities, and starting points for numeral formation. Use manipulatives alongside the numeral so students can connect the written number to its quantity.
• On-Level: Have students read and write numbers 0–20 independently and match numerals to their corresponding quantities.
• Enrichment: Give students mixed-up number cards and ask them to read, order, and write the numbers. Challenge them to write a number from a verbal clue, such as, “Write the number that comes after 14.”

Quick Formative Assessment

Hold up a numeral and ask students to read it aloud, then write it on a mini whiteboard. For teen numbers, follow up by asking students to show the number with a ten frame or manipulatives. This lets you quickly check numeral recognition, formation, and understanding of quantity.

Reading and Writing Number Words

Teach kids how to read number words as they learn to read. Teach each number word one at a time and how to spell them phonetically (when applicable).

Activities

• Use number posters with both the numeral and number word.
• Include number words on spelling lists so kids learn to read and spell number words.
• Use a number of the day routine to teach and focus on one word each day.
• Match number word cards with numeral cards (seen below).
• Play memory with a partner using number words and numeral cards. Look for pairs (e.g., 12 and 12).

• Build recognition and speed with mental math flashcards. Flashcards to kids, and they race to call out what they see (tally, numerals, number words, etc.).

Teacher Tip

Connect number words to quantities whenever possible instead of teaching them as isolated spelling words. When introducing a word such as fourteen, show the numeral 14 and a representation of 14 objects alongside it. Have students say the number, read the word, and match all three representations.

Differentiate

• Intervention: Begin with number words 0–10 and provide a numeral or picture representation as a visual support. Let students match words to numerals before expecting them to read or write the words independently.
• On-Level: Have students match, read, and write number words for numbers 0–20 and connect each word to its numeral.
• Enrichment: Mix numeral and number-word cards and ask students to match them, put them in order, and identify patterns they notice in teen number words.

Quick Formative Assessment

Show students a numeral and ask them to find or write the matching number word. For a quick check of understanding, reverse the task by showing a number word such as seventeen and asking students to write the corresponding numeral.

Build Number Sense by Counting On and Back

Teach the strategy of counting on and back from a number to prepare kids for addition and subtraction.

Activities

• Give students a number and a group of small objects to count on. Ask, “How many more do I have?” starting with 7 and using a group of 9 counters to count on.
• Play math games with small objects and decks of cards that require counting on.
• Play a group counting game called ‘Around the World.’ Say a number, and each person counts on and says the following number as you go around the circle.
• Use small objects to count on or back from a number given (cubes, counters, dice, etc.).
• Put numbers in backward order. Take the ordering activities seen above and reverse them.

Teacher Tip

Encourage students to start with the number they already have rather than counting from 1. For example, if a student has 7 counters and adds 3 more, say, “You already know you have 7. Start at 7 and count on: 8, 9, 10.” Use a number line or fingers at first, then gradually encourage students to count on mentally.

Differentiate

• Intervention: Begin with counting on within 10 and use a number line, fingers, or manipulatives as visual supports. Practice counting on one or two numbers at a time before increasing the amount.
• On-Level: Have students count on and back from numbers within 20 using manipulatives, number lines, or mental strategies.
• Enrichment: Give students a starting number and ask them to count on or back several numbers without manipulatives. Challenge them to explain how they found the answer.

Quick Formative Assessment

Say a number between 1 and 20 and ask students to count on three numbers. Then give them a different starting number and ask them to count back three numbers. Listen to whether students begin with the given number or restart at 1. You can also ask, “What number did you start with, and what number did you say next?” to check their understanding of the strategy.

Build Number Sense through Estimating

Give kids many opportunities to guess how many things they see daily. Ask prompting questions to encourage this thinking. Make sure kids know that they are estimating and that these are just guesses. Stress that estimates do not need to be exact but should be thoughtful. With more practice, estimates should get closer to the actual number of objects.

Activities

• Fill clear or open containers with different-sized objects for kids to guess. Keep it simple, then gradually increase the difficulty and object size. Smaller objects and bigger containers are usually more complex.
• Create an Estimation Station where containers containing objects can be examined closely, and children can make estimates.
• Play ‘Show & Hide’ with a partner. Use a cup and put some small counting bears inside. Quickly show your partner the bears and then hide them. They estimate, then you count together to check.
• Grab a pile of objects to show quickly for a whole-group activity. Cover them and have kids make guesses.

Teacher Tip

Ask students to explain what helped them make their estimate. Questions like “Did you notice about how many were in one group?” or “Does your estimate seem reasonable?” encourage students to use visual clues rather than choosing a random number. After revealing the actual amount, compare the estimate and answer without treating an incorrect estimate as a failure.

Differentiate

• Intervention: Start with small quantities within 10 and use objects that are easy to see and separate. Let students make an estimate, then count the objects together to connect estimating with actual quantities.
• On-Level: Have students estimate groups of objects within 20 and explain what helped them make their estimate.
• Enrichment: Challenge students to estimate larger groups or objects that are more spread out or clustered together. Ask them to make a second estimate after looking more closely and explain what changed their thinking.

Quick Formative Assessment

Quickly show a small group of objects and have students record their estimates on a mini whiteboard. Reveal the actual number and ask, “Was your estimate close? What did you notice that helped you?” This gives you a quick look at whether students understand estimation as a thoughtful approximation.

Build Number Sense by Comparing Numbers

As familiarity with numbers grows, so does the ability to compare them. Provide opportunities to compare numbers daily. Ask questions about which number is bigger, smaller, or the same.

Activities

• Use a chart or number line to compare numbers.
• Use small objects to facilitate comparison. For example, say, “Show 11 and 15 with cubes.” Then, ask, “Which number is smaller?”
• Teach the symbols <,>, and = and what each means. Use the alligator strategy (The alligator likes to eat the bigger number) to remember the signs and their meaning.
• Create number towers. Kids use cubes to form towers to represent numbers. Compare two towers to see the tallest and, therefore, the bigger number. The alligator eats the bigger tower.
• Compare numbers with math tools and indicate the correct symbol on clip cards (seen below). As kids become fluent, they should recognize the correct symbol without support.

Teacher Tip

Teach students to compare quantities first, then use the symbols. For example, have students build 11 and 15 with cubes and explain that 15 is greater because it has more cubes. Then introduce 15 > 11 as a way to record what they already understand. A visual strategy such as “the alligator opens toward the greater number” can help students remember the symbols, but make sure they can explain the comparison without relying on the mnemonic.

Differentiate

• Intervention: Compare concrete quantities within 10 before moving into teen numbers. Use cubes, counters, ten frames, or a number line and focus on the words greater than, less than, and equal to before introducing symbols.
• On-Level: Have students compare numbers within 20 and record their thinking using <, >, and =. Include comparisons such as 13 and 17, 16 and 12, and 14 and 14.
• Enrichment: Ask students to find multiple numbers that make a statement true. For example, “What numbers could make this true: 16 > ___?” Challenge them to explain how they know their answers work.

Quick Formative Assessment

Display two numbers between 11 and 20 and ask students to write the correct comparison symbol on a mini whiteboard. Follow up with, “How do you know?” to determine whether students understand the quantities or are simply remembering which way the symbol points.

Common Misconceptions About Numbers to 20

Numbers to 20 can be tricky for young learners, especially when they’re first working with teen numbers. Some common mistakes include:

• Reversing digits: Writing 14 as 41 or 17 as 71.
• Counting errors: Skipping numbers, double-counting objects, or losing track when counting a group.
• Teen number confusion: Knowing the digits individually but not understanding that the “1” in a teen number represents one ten.
• Number order: Struggling to identify which number comes before or after a given number.
• One-to-one counting: Saying numbers correctly but not matching each number to one object.

Explicit practice with counting, representing numbers with ten frames and manipulatives, and building teen numbers as 10 + some more can help students develop a stronger understanding of numbers to 20.

Number Sense Resources

You can find the activities in this post in the following resources on Teachers Pay Teachers.

• Numbers to 5 for Kindergarten
• Numbers to 10 for Kindergarten
• Numbers 11-20 for Kindergarten
• Mindful Math Kindergarten Curriculum
• Numbers to 10 for 1st Grade
• Numbers to 20 for First Grade
• Mindful Math First Grade Curriculum

Free Number Sense Puzzles to 20

Prep this fun set of number puzzles for your classroom centers and help kids build their number sense!

Click the image below to grab 20 FREE number puzzles, each with different representations.

Number Sense Books

• I Spy Numbers by Jean Marzollo
• 1,2,3 Peas by Keith Baker
• Chicka Chicka 1,2,3 by Bill Martin Jr.
• Splash! by Ann Jonas (counting)
• The Very Hungry Caterpillar by Eric Carle (counting)
• How Do Dinosaurs Count to 10? by Jane Yolen
• Number Everywhere by Elliot Kaufman
• 10 Black Dots by Donald Crews
• How Many Bugs in a Box? by David Carter
• How Many Snails? by Paul Giganti, Jr.
• Ten Sly Piranhas by William Wise
• None the Number by Oliver Jeffers
• Zero the Hero by Joan Holub
• More or Less by Stuart Murphy
• Tally O’Mally by Stuart Murphy
• Place Value by David Adler
• What’s the Place Value by Shirley Duke
• Quack and Count by Keith Baker
• Betcha! by Stuart J. Murphy

Try the Mindful Math Comprehensive Program

Read about the Mindful Math program and how it can positively change your math block! This comprehensive math curriculum bundle is available for Kindergarten, first grade, and 2nd grade.

More about Teaching Number Sense

Building Number Sense free email series

Number of the Day Activities

5 Tips for Building Math Fluency

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