Numbers to 100: Tens and Ones

Active learning works for this topic because children need to see, touch, and move physical representations of tens and ones to build mental images of place value. When students group, trade, and count with their hands, they connect abstract symbols to concrete quantities, which research shows strengthens long-term understanding.

• Primary 1
• Mathematics
• 4 activities
• 20 min–35 min

Learning Objectives

1. Identify the number of ones that make up one ten.
2. Represent two-digit numbers by composing tens and ones using base-ten blocks.
3. Compare two-digit numbers based on their tens and ones composition.
4. Calculate the total value of a two-digit number given its tens and ones components.
5. Explain how grouping objects into tens aids in counting larger quantities.

Experiential Learning

⏱ 30 min·Pairs

Block Build: Tens and Ones Representation

Provide base-ten blocks to pairs. Call out numbers from 11 to 99; students build each with tens rods and ones cubes, then state the tens and ones aloud. Partners verify and record on mini-whiteboards before trading roles.

Prepare & details

How many ones make one ten?

Facilitation Tip: During Block Build, circulate and ask pairs to explain why they exchanged 10 ones for 1 ten, reinforcing the exchange concept through verbal reasoning.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 25 min·Small Groups

Tens Relay Race: Counting in Tens

Divide class into small groups and set up number lines on the floor. First student in line jumps 10 units forward saying the number, tags next student who continues from there to 100. Groups race while practicing skip-counting.

Prepare & details

How do we use tens and ones to describe a two-digit number?

Facilitation Tip: For Tens Relay Race, stand at the finish line to time each team and prompt students to say the tens number out loud as they land, linking movement to number words.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 35 min·Individual

Straw Bundling: Grouping Ones into Tens

Give students straws or popsicle sticks individually. They bundle 10 into a ten, then create target numbers like 47 with bundles and singles. Share and compare bundles with the class.

Prepare & details

How does understanding tens and ones help us count bigger numbers?

Facilitation Tip: When setting up Straw Bundling, model bundling 10 straws with a strong knot, then count the bundles aloud to emphasize the unitizing of tens.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 20 min·Whole Class

Place Value Charts: Whole Class Matching

Project a large place value chart. Students hold tens and ones cards; teacher says a number, students place cards correctly on their desks first, then justify as a class.

Prepare & details

How many ones make one ten?

Facilitation Tip: Before Place Value Charts, demonstrate sorting a handful of counters into the correct columns while thinking aloud about why each counter belongs in that place.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Teaching This Topic

Start with concrete manipulatives to build a solid foundation, then move to pictorial representations like drawings or charts before introducing abstract symbols. Avoid rushing to written numbers; give students time to internalize the concept through repeated hands-on experiences. Research suggests that children who struggle benefit from verbalizing their grouping strategies as they work, which clarifies their thinking and reveals misconceptions early.

What to Expect

Students will confidently explain that 10 ones make 1 ten, build two-digit numbers correctly with base-ten blocks, and count forward or backward in tens to 100. They will use the words 'tens' and 'ones' accurately when describing numbers and grouping quantities.

Watch Out for These Misconceptions

Common Misconception

During Block Build, watch for students who count all the blocks as ones without grouping them into tens.

What to Teach Instead

Ask the pair to recount the ones, and then physically group 10 ones together. Have them trade the group for a ten rod, and ask, 'Now how many tens and how many ones do you have? Explain your thinking to your partner.'

Common Misconception

During Tens Relay Race, watch for students who start counting from 1 instead of counting by tens (e.g., 1, 2, 3 instead of 10, 20, 30).

What to Teach Instead

Stand beside the number line and model starting at 10, then point to each jump while counting aloud with the student. Ask, 'What number will you land on next? How do you know?'

Common Misconception

During Place Value Charts, watch for students who place counters in the wrong column without realizing the value of each place.

What to Teach Instead

Hold up a counter and ask, 'If this counter is in the ones column, what does it represent? What if it moves to the tens column?' Have the student physically move a counter between columns while explaining the change in value.

Assessment Ideas

Exit Ticket

After Block Build, give each student a card with a two-digit number such as 42. Ask them to draw base-ten blocks to represent the number and write a sentence explaining how many tens and how many ones are in 42.

Quick Check

During Tens Relay Race, listen for students to say the correct tens numbers as they jump. Ask them to explain how they knew which number to land on next.

Discussion Prompt

After Straw Bundling, pose the question: 'Imagine you have 73 counters. How could you group them to count them faster? Explain your strategy using the words 'tens' and 'ones'.'

Extensions & Scaffolding

• Challenge: Ask students to build a number like 87 using base-ten blocks and then represent it with a drawing. Next, have them write a riddle for a partner to solve using their drawing and the words 'tens' and 'ones'.
• Scaffolding: For students who confuse tens and ones, provide a sorting mat with two labeled columns and have them place pre-counted groups of objects into the correct column while naming each group as 'tens' or 'ones'.
• Deeper exploration: Introduce counting by tens from any starting number, such as 23, and ask students to use a number line or hundred chart to find the next three tens numbers in the sequence.

Key Vocabulary

Ones	Individual units that represent the count of single objects. In a two-digit number, the ones digit shows how many are left after making as many tens as possible.
Tens	Groups of ten ones. The tens digit in a two-digit number indicates how many groups of ten are present.
Base-ten blocks	Manipulative tools used to represent numbers. Unit cubes represent ones, and rods represent tens.
Place value	The value of a digit based on its position within a number. For example, in 36, the 3 is in the tens place and the 6 is in the ones place.