Students answer questions correctly to collect treasure from the bottom of the ocean floor. Each piece of treasure is worth different amounts of points. The winner is the person with the most points at the end of the game!

Use this game to reinforce the skill of adding ten when mentally adding simple sums to 20. Students will practise recognising number patterns and develop fluency in using mental maths strategies to quickly add 10 to a given number. Each correct answer helps them collect a piece of treasure, with different values adding a layer of excitement and challenge to the game.

Who will collect the most treasure and become the champion of the sea?

Key Learning Outcomes:

• ✅ Add 10 to numbers mentally within 20
• ✅ Recognise number patterns related to place value
• ✅ Strengthen mental maths fluency and confidence
• ✅ Develop number sense through repeated practise
• ✅ Engage in interactive, competitive gameplay to reinforce learning

How to Play:

1. Students are presented with a simple equation requiring them to add 10 to a given number.
2. They must select the correct answer.
3. Each correct answer allows them to collect a piece of treasure from the ocean floor.
4. Each treasure is worth a different number of points.
5. The game continues until all questions have been answered, and the player with the most points wins!

Ideas for Classroom Use:

• 💡 Use during warm-up sessions or maths rotations to reinforce mental addition strategies
• 💡 Great for Foundation to Year 1 students developing confidence with number patterns
• 💡 Pair with hands-on resources like ten frames to support understanding of adding 10
• 💡 Replay the game regularly to build speed and fluency

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 fluency-building or revision activity

Let’s Sail – Mental Maths: Adding 10 supports number fluency and confidence as students collect treasure while practising essential maths skills under the sea!