The counting game

counting back

Watch the video to learn how to play

Transcript

All right, hi everybody, I'm here with Ayesha today. Hi Ayesha.

Hi Michelle, how are you today?

I am excellent because we're about to play one of my favourite Maths games. How are you?

I'm very excited too this sounds good.

OK, so I know you've been playing the counting game, but I think you've been playing it so you're always counting up to a number?

That's correct.

And today what we were thinking about is we could show how you can also play it in the reverse so our target today is zero.

OK.

And also we wanted to show you how when you're playing this game you can use some equipment to help you. So, I've got these bundles of paddle pop sticks over here. Um now I know how much is in them because I've made them, but what do you think when you see this?

Hmmm, I think there might be ten in there. So I might double check that if that's OK.

Of course, it's exactly what mathematicians should do. So I can see that there's three and two more, which is 5. I'm noticing there's another five there, and together that's 10, so I trust that these are going to be 10. Because if you laid them along side you can see that pretty much 10. So we need to workout how many we have. But because we've been learning about other ways of determining how many without having to count we could organize our collection so that we can see how many that we have and use our skills of looking at thinking. What a great idea!

I've got an idea. Ok. Why don't we use a ten frame.

Great idea!

Oh I can see what you're imagining in your brain there is Ayesh is that there's like a 10 frame around that. Is that right?

Spot on, and I know then I can go like this. That will mean that I have 10 boxes or rectangles uh-huh and so one whole 10 frame, an one more than 11 and eleven 10s. We rename that is 110.

Alright, so that's where we're starting from today, 110. So Ayesha when you play you can take away 1, two or three of our bundles and we count back at the same time and you can start because I'll also show you how we can record our thinking.

Sounds good. So I will take 2 bundles away, so that's 100. 90.

Ok. And I think I might say um take away two also some now 80 and 70. And can you record my thinking there Ayesh?

80, 70 Your go.

I'm going to take away three bundles, so sixty, fifty, forty.

OK, I'm going to take away one more so it is down to 30 three tens. 30.

And I can take away the three 10s that are the left, so 20, 10, zero.

Congratulations. Good game! Alright now what I wonder Ayesha is if our friends at home would like to have a play, you can start from any number that you like. We started at 110 today but I also wonder if I could have done something differently to have won. Wonder what you could have done? Over to you.

Collect resources

You will need:

  • pencils or markers

  • your mathematics workbook.

Instructions

  • Select a starting number for example 110.

  • Then select a unit value for example, tens.

  • The goal is to be the player who says zero.

  • Players can count back by saying the next 1, 2 or 3 number words in the tens sequence.

  • Players collect a counter (or a tally mark) if they say the target number. A new target number is chosen and players play again.

  • For example:

Target number 0 (starting at 110 and counting in tens)

Player A: 100...

Player B: 90, 80...

Player A: 70...

Player B: 60...

Player A: 50, 40...

Player B: 30, 20, 10...

Player A: zero!

  • Player A collects a counter (or tally mark!)

Discuss

  • What would happen if I had said... instead of ...? (Identify a point time, when playing the game, to ask this question.)

  • How could we change the game to make it more/less challenging?

  • What did you notice about playing the game by counting backwards? Did it make your brain work harder or was it less difficult?

  • Did you work out a way to play this game so that you didn’t lose? What was your strategy? Did it work?

Share/submit

Share your work with your class on your digital platform.

You may like to:​

  • write comments​

  • share pictures of your thinking​

  • comment on the thinking of others.