Math Games and Fun

Overview

In this lesson, students practise adding and subtracting two- and three-digit numbers using place value partitioning and regrouping strategies, through short, structured games. The lesson builds on earlier work with number facts and mental strategies, moving towards efficient calculations without a calculator.

Learning intentions

• WALT add and subtract two- and three-digit numbers using place value to partition and regroup.
• WALT explain my thinking using diagrams, part-part-whole models, and number sentences.
• WALT choose a strategy that helps me calculate accurately and efficiently.

Success criteria

Students can:

• I can partition numbers into hundreds, tens and ones to help me add or subtract.
• I can regroup (trade tens for ones, or hundreds for tens) when subtraction or addition requires it.
• I can represent my strategy using a model (place value blocks/part-part-whole/number line) and a matching number sentence.
• I can check the answer using the inverse relationship between addition and subtraction.

Curriculum links

• Number — VC2M3N04: adding and subtracting two- and three-digit numbers using place value to partition, rearrange and regroup.
• Number — using partitioning and part-part-whole models and the inverse relationship between addition and subtraction to solve problems without a calculator.

Lesson structure (60 minutes)

1. 0–5 min · Hook (Think, pair, share). Teacher displays two problems on the board: 485 + 365 and 763 − 528. Students silently estimate first, then pair-share which parts of the numbers they would combine or compare.

2. 5–12 min · Minilesson (Strategy recap + model). Teacher models one example using a part-part-whole diagram and partitioning (hundreds, tens, ones), including regrouping. Students copy the model in their books and label what happens to each place value when regrouping is needed.

3. 12–22 min · Game 1: Place Value Race (Pairs).

• Teacher sets up cards with two- and three-digit addition/subtraction questions and corresponding place value grids (hundreds/tens/ones).
• Students in pairs take turns drawing a card, partitioning both numbers, calculating, and writing a number sentence.
• The “race” is to complete: partition → regroup (if needed) → compute → quick check using inverse. Teacher circulates, listening for correct partitioning, accurate regrouping, and clear explanations.

4. 22–35 min · Game 2: Regrouping Towers (Small groups of 3–4). Each group has plastic place value blocks or paper place value strips.

• Students roll dice to generate a target equation (e.g., 3-digit − 2- or 3-digit).
• They build the first number, then remove the second number, showing regrouping when a column would go negative.
• They record the result with a number sentence and a brief explanation (“I regrouped because…”). Teacher prompts groups to justify regrouping with place value language (ones, tens, hundreds).

5. 35–45 min · Game 3: Inverse Check Challenge (Whole class relay). Teacher gives one completed answer card (students see a question + an answer).

• Teams must produce the inverse subtraction/addition to verify correctness.
• For example, if the given statement is 623 − 318 = 305, students confirm with 305 + 318 = 623 (or the matching inverse). Teacher checks that students understand why inverse operations help detect errors.

6. 45–55 min · Independent practice (Choice board). Students choose 2 tasks from a board (teacher-selected to match the same VC2M3N04 focus):

• Task A: Solve 2 addition questions using partitioning diagrams.
• Task B: Solve 2 subtraction questions including at least one regrouping.
• Task C: Match each question to the correct partitioning model and number sentence. Students show working using place value partitioning and at least one short check (inverse or reasonableness).

7. 55–60 min · Exit ticket (Quick assessment). Students complete one question on the exit ticket: a three-digit subtraction that requires regrouping, e.g., 704 − 389. They must draw a partition diagram and write the number sentence, plus one sentence checking the answer.

Resources

• Question cards (two- and three-digit addition and subtraction) with spaces for number sentences
• Place value grids (hundreds/tens/ones) for recording
• Dice or digital dice (optional) for generating numbers
• Base ten blocks or paper place value strips for regrouping towers
• Small whiteboards or scrap paper for groups to record answers
• Exit ticket slips
• Teacher model diagram (part-part-whole)

Assessment

• Formative teacher observation during Game 1 and Game 2: correct partitioning, accurate regrouping, and clarity of explanation.
• Targeted questioning: “Which place value did you regroup?” “How do you know your answer is reasonable?”
• Exit ticket checked for representation (diagram/number sentence) and correctness.

Differentiation

• Support: provide sentence starters (“I partitioned…”, “I regrouped because…”, “I checked using inverse…”) and pre-made partially completed models for some students.
• Support: offer an optional number line or regrouping “hint strip” (e.g., 10 ones = 1 ten) to reduce memory load.
• Extension: for students ready, include an “efficient strategy” prompt (e.g., “Which partitioning would make this easier: standard partition or another arrangement?”) and ask them to explain why.
• Additional challenge within games: ask students to create their own equation card from a given partition (e.g., “Make a subtraction where ones require regrouping.”).
• EAL/SEN: use consistent terminology (hundreds, tens, ones), visual models, and allow oral explanation alongside written answers.

Differentiation (advanced learners)

• Extension activity (integrated during Game 1/2): “Create and solve a new card” using the same numbers but a different strategy. Students must record two methods (e.g., partition with regrouping and inverse-check using a model).
• Extension question for independent practice: include one problem where careful regrouping avoids mistakes, and require a written justification of regrouping choices.