Rekenrek duel

Hello there mathematicians, we hope you're having a really lovely day today.

We're going to show you a new game called Rekenrek duel. Now there's lots of different ways you can play this game and we're going to show you one way today.

And today playing our game is our king of the jungle, the great lion.

And we also have our giraffe and I think actually, well, this is quite fitting actually. His head's a bit too big, so I'll move him down so that you can see our giraffe. And we're going to represent our king of the jungle with black and our giraffe with orange 'cause he's got an orange body or partly orange body. So how you play is that you need some number cards from zero through to twenty, and you shuffle them up, and you put them in the central pile and you turn over a card.

And the lion can go first today and he needs to be able to move six across on his rekenrek in just one or two slides only. So the lion might think, well, I know six is five, and one more. So that's two slides. He could also think. Well, I know six is three and three. Double three is six or he could say something like, I know six is four and if I look at this chunk here and that's five and leave one behind that's four and one more. Oops is five, so four and two is six and, so then he could say six is four and two.

And then put the card to the bottom, and it's now giraffes turn.

And giraffe has to make sixteen in one or two slides only. So the giraffe is thinking what do I know about sixteen? I know it's one, ten and six more. So one slide could be moving across one, ten. And then how could I make six? Uh-huh, yes, because there's a chunk of five and one more, makes six. So that's how he could make sixteen.

So he has to think about recording sixteen is one, ten and six. And yes, the card goes on the bottom and then it's the lions turn again.

Ok, mathematicians, how would you make eight in one move? What are you thinking? One or two slides only.

Ah, nice thinking, yeah.

So you could do double four. So if I know this chunk is five, that means if I leave one behind, this must be four because four is one less than five. Look, so that would be one, four and I use the same strategy for another four. Double four is eight. Yes, and some of you are thinking, well you could think about eight is two less than ten. So do the two left behind strategy. Uhm, that is also eight.

Yes, and some of you are thinking eight is also five and oops. three.

Alright, over to you mathematicians to play Rekenrek duel.

So what's some of the mathematics here?

This game encourages students to think about important relationships, such as how many more or less are needed to get to the nearest five or ten. To notice, develop and use part-part-whole number knowledge and to use numbers flexibly. These are all essential to being able to develop and use flexible strategies when working in additive and multiplicative situations.

Have fun mathematicians! Until we meet again.