Mathematics · Year 2

Active learning ideas

Subtracting Two-Digit Numbers (With Regrouping)

Active learning works for subtracting two-digit numbers with regrouping because children need to see and touch the exchange of tens and ones. Concrete tools like base ten blocks let students physically trade a ten rod for ten unit cubes, making the abstract concept of regrouping visible and memorable.

• National Curriculum Attainment Targets
• KS1: Mathematics - Addition and Subtraction

• 20–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Regrouping Blocks

Prepare stations with base ten blocks and subtraction cards like 43 - 28. Students model the top number, exchange a ten for ones if needed, subtract bottom number, and record. Rotate groups every 10 minutes, then share one insight as a class.

Explain the process of regrouping (borrowing) when the ones digit in the top number is smaller.

Facilitation Tip

During Station Rotation: Regrouping Blocks, circulate and ask each pair to explain their exchange step aloud before writing the number sentence.

What to look for

Present students with the problem 73 - 28. Ask them to solve it using base ten blocks and draw a picture of their steps, including the regrouping. Observe if they correctly exchange a ten for ten ones.

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

Activity 02

• Outdoor Investigation Session
• 25 min · Pairs

Pairs: Number Line Borrow

Give pairs a large number line and cards like 52 - 37. Jump back tens first, then ones, borrowing by partitioning the top number. Partners check by adding back up. Draw their jumps on mini whiteboards.

Critique different methods for subtracting with regrouping, such as using a number line or base ten blocks.

Facilitation Tip

During Pairs: Number Line Borrow, remind students to mark the borrow point on the number line with a small arrow to show the shift in value.

What to look for

Pose the question: 'Why do we sometimes need to 'borrow' from the tens place when subtracting? Use the example 51 - 24 to explain your thinking.' Listen for explanations that involve the ones digit being too small to subtract.

• Remember
• Understand
• Analyze
• Social Awareness
• Self-Awareness
• Decision-Making

Activity 03

• Outdoor Investigation Session
• 30 min · Whole Class

Whole Class: Word Problem Chain

Start with a scenario like '45 apples minus 28 eaten.' Students in a circle add details requiring regrouping, solve using drawings or blocks, pass to next. Teacher scribes on board for all to see.

Construct a word problem that requires subtraction with regrouping to solve.

Facilitation Tip

During Whole Class: Word Problem Chain, pause after each problem to ask a volunteer to restate the problem in their own words before solving it.

What to look for

Give each student a card with a word problem like: 'Sarah had 35 stickers. She gave 17 stickers to her friend. How many stickers does Sarah have left?' Students must write the number sentence and solve it, showing their regrouping steps.

• Remember
• Understand
• Analyze
• Social Awareness
• Self-Awareness
• Decision-Making

Activity 04

• Outdoor Investigation Session
• 20 min · Individual

Individual: Pictorial Match-Up

Provide worksheets with pictorial subtractions and mixed methods. Students match problems to correct drawings showing regrouping, then create one themselves. Collect for quick plenary feedback.

Explain the process of regrouping (borrowing) when the ones digit in the top number is smaller.

What to look for

Present students with the problem 73 - 28. Ask them to solve it using base ten blocks and draw a picture of their steps, including the regrouping. Observe if they correctly exchange a ten for ten ones.

• Remember
• Understand
• Analyze
• Social Awareness
• Self-Awareness
• Decision-Making

A few notes on teaching this unit

Teach this topic by moving from concrete to pictorial to abstract, using base ten blocks first to model regrouping. Avoid rushing to abstract methods before students can explain the exchange in their own words. Research shows that students who verbalise their steps while using manipulatives develop stronger number sense. Use consistent language like 'trade one ten for ten ones' to reinforce place value understanding.

Students will confidently explain and perform regrouping when subtracting two-digit numbers. They will use base ten blocks, number lines, and pictorial methods to solve problems accurately, showing their steps with clear reasoning. Misconceptions about borrowing will be corrected through guided practice and discussion.

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Watch Out for These Misconceptions

• During Station Rotation: Regrouping Blocks, watch for students who subtract the ones without exchanging a ten. Redirect them by asking, 'Can you take away 8 ones from 3 ones? What can we trade to make this possible?'

  During Station Rotation: Regrouping Blocks, pair students to verbalise the exchange step before writing the number sentence. Listen for language like 'We trade one ten for ten ones because we need more ones to subtract.' This builds correct habits through peer explanation.

• During Station Rotation: Regrouping Blocks, watch for students who believe trading a ten for ones reduces the number's total value. Ask them to count the total value before and after the exchange to see it remains the same.

  During Station Rotation: Regrouping Blocks, guide students to recount the value of the blocks after trading one ten for ten ones. Ask, 'How many tens and ones do we have now? Is the total still the same?' This reinforces place value invariance through hands-on comparison.

• During Individual: Pictorial Match-Up, watch for students who doubt pictorial representations can represent regrouping. Ask them to match their drawing to a base ten block arrangement and explain how both show the same exchange.

  During Individual: Pictorial Match-Up, have students pair their drawings with base ten block setups and explain how the exchange looks in both forms. Discuss how the pictures prove consistency across tools, bridging to mental math.

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Methods used in this brief

• Stations Rotation
• Outdoor Investigation Session