Mathematics · Grade 1

Active learning ideas

Comparing Numbers to 100

Active learning transforms abstract comparisons into tangible experiences. When students build numbers with blocks, walk number lines, or handle symbol cards, they internalize concepts through touch and movement. These kinesthetic and visual experiences make relationships between quantities memorable and meaningful for young learners.

• Ontario Curriculum Expectations
• 1.NBT.B.3

• 20–35 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Placemat Activity
• 25 min · Pairs

Block Comparisons: Build and Compare

Pairs select two numbers under 100, build each with base-ten blocks, then place >, <, or = between them and explain using place value. Switch numbers and repeat. Record one comparison on chart paper.

Justify how we can prove that one number is greater than another using physical tools or drawings.

Facilitation Tip

During Block Comparisons, circulate and ask students to explain their block groupings aloud to reinforce vocabulary.

What to look for

Present students with two groups of base-ten blocks (e.g., 3 tens and 4 ones vs. 2 tens and 8 ones). Ask them to state which group is greater and why, using the correct mathematical language.

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

Activity 02

• Placemat Activity
• 30 min · Small Groups

Number Line Walks: Position Predictions

Create a floor number line to 100. Small groups draw two cards with numbers, predict which is greater by walking to positions, then confirm and insert symbol. Discuss predictions.

Predict what happens to the value of a number when we add one more ten versus one more one.

Facilitation Tip

In Number Line Walks, have students pause at each step to verbalize their current number and the next one aloud.

What to look for

Give each student a card with two numbers (e.g., 45 and 52). Ask them to write the correct symbol (<, >, or =) between the numbers and then draw a picture or use words to explain their choice.

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

Activity 03

• Placemat Activity
• 35 min · Small Groups

Estimation Jars: Group Challenges

Fill jars with objects under 100. Individuals estimate, then small groups compare estimates using symbols and recount exactly. Chart comparisons to spot patterns.

Evaluate why it is useful to estimate a quantity before we count it exactly.

Facilitation Tip

For Estimation Jars, rotate partners so students discuss their initial guesses before opening the jar to count.

What to look for

Pose a scenario: 'Imagine you have 25 stickers and your friend has 35 stickers. Who has more? How do you know?' Encourage students to use comparative language and justify their answers.

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

Activity 04

• Placemat Activity
• 20 min · Pairs

Symbol Snap: Card Game

Pairs draw number cards, snap if >, <, or = applies, and state the relation. Use visuals like alligator mouths for symbols. Play three rounds, tally wins.

Justify how we can prove that one number is greater than another using physical tools or drawings.

What to look for

Present students with two groups of base-ten blocks (e.g., 3 tens and 4 ones vs. 2 tens and 8 ones). Ask them to state which group is greater and why, using the correct mathematical language.

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

A few notes on teaching this unit

Start with concrete tools like base-ten blocks to build numbers, then transition to visuals like number lines and symbols. Always connect symbols to physical actions: the 'hungry alligator' can 'eat' the larger block tower. Avoid rushing to abstract symbols until students demonstrate understanding through hands-on comparisons. Research shows that students who physically manipulate objects before using symbols develop stronger number sense and retain concepts longer.

Successful students will speak confidently about numbers using terms like 'greater than,' 'less than,' and 'equal to.' They will justify comparisons with physical tools, predict changes when adding tens or ones, and estimate before counting precisely. Their explanations should connect numbers to real-world contexts and show flexibility in representing equal values.

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Watch Out for These Misconceptions

• During Block Comparisons, watch for students who focus only on the ones digit when comparing numbers like 19 and 20.

  Guide students to build both numbers side-by-side using base-ten blocks, then ask them to regroup ones into a ten to see the true magnitude difference between 19 and 20.

• During Symbol Snap, watch for students who believe the greater-than symbol points to the smaller number because the 'mouth' opens that way.

  Use alligator cutouts with the open mouth facing the larger block tower during comparisons, reinforcing that the symbol always directs toward the greater quantity.

• During Block Comparisons or Estimation Jars, watch for students who assume equality means identical appearance rather than equal value.

  Have students compare sets of objects or block towers for one-to-one matching, then model trading activities where 5 tens equals fifty ones to demonstrate flexible equivalence.

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Methods used in this brief

• Placemat Activity