Gear up and get ready to defend! In this strategic digital game, students protect their base by applying their estimation and rounding skills to answer practical maths questions. Each correct answer activates a defence move to stop the invaders—before they reach the base!

Throughout the game, students will tackle multiple-choice questions that involve rounding whole numbers and estimating sums, differences, and totals. Scenarios include everyday and financial contexts, such as: “Estimate the total cost of $28.75 and $31.20.” This helps develop reasoning, number sense and confidence in using mental strategies to check the reasonableness of their answers.

As students work to defend their base, they’ll sharpen real-world maths skills and strengthen their ability to quickly estimate with accuracy.

Key Learning Outcomes:

• ✅ Round numbers to the nearest 10, 100 or other place value
• ✅ Estimate outcomes of addition and subtraction problems
• ✅ Apply mental computation strategies in everyday contexts
• ✅ Use estimation to check the reasonableness of results
• ✅ Engage in interactive, problem-solving gameplay through maths content

How to Play:

1. Students are presented with a rounding or estimation problem and multiple answer choices.
2. A correct answer triggers a defence move to block incoming invaders.
3. An incorrect answer lets the invaders advance closer to the base!
4. The game continues through a series of practical estimation challenges.
5. Students aim to defend their base by answering accurately and efficiently.

Ideas for Classroom Use:

• 💡 Use during number sense or money units to consolidate estimation strategies
• 💡 Great for Year 4–5 students applying rounding to real-life maths contexts
• 💡 Pair with hands-on shopping activities, budgeting tasks or estimation games
• 💡 Use in numeracy rotations as a fluency or problem-solving station

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 – Estimation & Rounding brings real-world number sense to life—giving students the tools to estimate, round, and reason with confidence while defending their base!