This game offers children a motivating context in which to practise mental addition and subtraction. It also encourages recognition of number bonds and will help develop an understanding of equivalence.
Begin by introducing the class to the printable cards before the interactivity. Give out sets of cards to each pair of learners and encourage them to lay them all out, face-up. You could offer any of the following prompts to encourage them to engage with the representations on the cards:
Once learners have explored the cards in some of these ways, show them the interactivity. You may like to begin to play the game on the interactive whiteboard with the whole group. You could choose a card and, before turning over a second card, invite learners to talk in pairs about what might match. As more cards are revealed, trying to remember which cards have already been seen and what they have on them becomes important too.
As soon as the class has a flavour of the game, suggest that they work in pairs at a computer, laptop or tablet. (They could use the printable cards if this is not feasible.) As they play in pairs, watch and listen, and make a note of anything you overhear that you'd like to refer to during a mini plenary. It may be that you notice a misconception more than once, or that you'd like to spend a few minutes inviting learners to explain how they knew that two particular cards are a match.
You could return to the interactivity in subsequent lessons, perhaps as a starter or during a plenary, where appropriate.
What might the matching pair for that card have on it?
How do you know those two cards match?
Have we already seen a card that might be a match for that one?
Playing the game with all the cards face-up is a great way to focus on the mathematics if the memory aspect proves tricky for some children. You can do this in this version of the interactivity.
Some pairs may enjoy challenging themselves to get as many points as possible using this version of the interactive game and/or trying to complete the game as quickly as possible (this version of the interactivity has a timer). Some of the suggestions in the opening paragraph of the 'Possible approach' above would make good extension tasks.