Mathematics · Grade 2

Active learning ideas

Comparing Numbers to 200

Active learning strategies like Station Rotation and Gallery Walk help students internalize skip counting patterns by engaging them kinesthetically and visually. These methods move beyond rote memorization, allowing students to discover and articulate the predictable sequences in numbers up to 200.

• Ontario Curriculum Expectations
• 2.NBT.A.4

• 15–45 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Pattern Detectives

Set up stations with different tools: a hundred chart with counters, a long floor number line, and a set of Canadian coins. At each station, students must skip count by a different interval (2, 5, 10, or 25) and record the 'ending digit' patterns they notice.

How can you tell which of two numbers up to 200 is greater?

Facilitation Tip

During the Station Rotation, ensure students rotate through all stations, spending adequate time at each to explore the skip counting patterns using the different tools.

What to look for

Provide students with three pairs of numbers up to 200 (e.g., 135 and 153, 102 and 120, 188 and 188). Ask them to write the correct comparison symbol (>, <, =) between each pair.

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

Activity 02

• Think-Pair-Share
• 15 min · Pairs

Think-Pair-Share: The Broken Calculator

Tell students their '+' key only works for one number (e.g., +5). Ask pairs to figure out how many 'clicks' it takes to get from 0 to 50, and then from 5 to 55. They share their strategies for keeping track of the counts.

What do you look at first when comparing two three-digit numbers?

Facilitation Tip

In Think-Pair-Share, prompt pairs to not only find the answer but also explain the specific rule their 'broken calculator' is using to arrive at the sequence.

What to look for

Display two numbers on the board, such as 172 and 165. Ask students to hold up fingers to represent the hundreds digit, then the tens digit, then the ones digit for each number. Then, ask them to use their hands to show the '>' or '<' symbol to compare the numbers.

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

Activity 03

• Gallery Walk
• 30 min · Small Groups

Gallery Walk: Pattern Posters

Groups create a visual representation of a skip counting sequence (e.g., counting by 2s starting at 1). They highlight the pattern in the ones place. Students walk around with sticky notes to comment on patterns they see in other groups' work.

Can you put a set of numbers up to 200 in order from least to greatest on a number line?

Facilitation Tip

During the Gallery Walk, encourage groups to use precise mathematical language when describing their skip counting posters and to ask clarifying questions of other groups' work.

What to look for

Present students with the numbers 148 and 142. Ask: 'Which digit do you compare first? Why? What happens if the hundreds digits are the same? What happens if the tens digits are also the same?' Guide them to explain their reasoning for comparing the ones digits.

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

A few notes on teaching this unit

Teachers can effectively teach skip counting by emphasizing the underlying patterns rather than just memorization. Using tools like hundred charts and number lines, especially for transitions across hundreds, helps students visualize the consistent increments. Explicitly discussing place value shifts during skip counting solidifies understanding.

Students will confidently identify, extend, and explain skip counting patterns by 2s, 5s, 10s, and 25s up to 200. They will be able to compare numbers within this range, articulating their reasoning based on place value understanding.

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Watch Out for These Misconceptions

• During the Station Rotation activity, watch for students who only focus on counting by 10s starting from multiples of 10.

  Redirect students to the hundred chart station and ask them to identify the pattern when counting by 10s starting from a number like 7 (7, 17, 27...), highlighting how the ones digit remains constant.

• During the Station Rotation, observe students who struggle to transition their skip counting sequence when crossing the 100 mark.

  Guide students to use the floor number line, having them physically jump from 95 to 105 and call out the numbers, emphasizing the transition into the next hundred block.

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Methods used in this brief

• Stations Rotation
• Think-Pair-Share
• Gallery Walk