The robots are closing in! In this action-packed digital game, students work together to defend a town under attack by solving perimeter challenges involving composite shapes. Every correct answer gives them the power to choose whether to build homes, strengthen the town walls, or launch an attack on the incoming robots.

Students are presented with a variety of composite shapes made from rectangles and other familiar forms, with sides labelled in millimetres (mm), centimetres (cm), or metres (m). They must calculate the total perimeter of each shape using the given dimensions, applying their understanding of measurement units, addition strategies, and composite shape reasoning.

With each correct answer, the town grows stronger. But beware - incorrect answers give the robots a chance to break through. Can your students defend the town before it's too late?

Key Learning Outcomes:

• ✅ Calculate the perimeter of composite shapes
• ✅ Use and convert between metric units of measurement (mm, cm, m)
• ✅ Apply addition strategies to multi-sided figures
• ✅ Recognise and solve problems involving composite shapes
• ✅ Engage in decision-making gameplay that reinforces measurement skills

How to Play:

1. Students are shown a composite shape with side lengths labelled in mm, cm, or m.
2. They must calculate the total perimeter by adding all visible side lengths.
3. A correct answer allows them to choose whether to grow the town, build the walls, or attack the robots.
4. Incorrect answers allow the robots to advance.
5. The game continues until all questions are answered - will the town be saved?

Ideas for Classroom Use:

• 💡 Use during measurement or geometry units to reinforce composite shape concepts
• 💡 Ideal for Years 4–6 students working on perimeter, metric units, and addition fluency
• 💡 Pair with cut-and-measure shape building tasks for a hands-on connection
• 💡 Add to rotations or assign as a maths challenge for fast finishers

Top Teacher Tips:

• 💛 Let students personalise their experience by choosing from six characters before the game begins
• 💛 Select the number of players or teams at the start of the game to suit individual, paired, or group play
• 💛 Send the QR code home for students to play as a homework or revision task

Let’s Defend – Calculating the Perimeter of Composite Shapes turns geometry into an adventure where maths skills protect a town and save the day!