# Double hunt

ES1 – A thinking mathematically targeted teaching opportunity focussed on collecting representations of doubles

## Syllabus

Syllabus outcomes and content descriptors from Mathematics K–10 Syllabus © NSW Education Standards Authority (NESA) for and on behalf of the Crown in right of the State of New South Wales, 2023

• MAO-WM-01
• MAE-RWN-01
• MAE-RWN-02
• MAE-CSQ-01
• MAE-CSQ-02
• MAE-FG-02

## Collect resources

You will need:

• something to write with.

• something to write on.

## Watch

Watch Double hunt part 1 video (4:08).

Explore ways to sort dominoes by doubles and not doubles.

These videos were created with Kim from Mullumbimby PS.

### Transcript of Double hunt part 1

(Duration: 4 minutes and 8 seconds)

[Text over a navy-blue background: Double Hunt. Small font text in the lower left-hand corner reads: NSW Mathematics Strategy Professional Learning Team (NSWMS PL team). In the lower right-hand corner is the waratah of the NSW Government logo.]

### Speaker

Let's play double hunt!

[Text over a white background: You will need…

· something to write on

· something to write with.]

### Speaker

For today's activity, you will need something to write on and something to write with.

[Text over a blue background: Let’s explore!]

### Speaker

Let's explore!

[Two coloured sheets of paper, which are joined together, are laid out over a wooden surface. The piece of paper on the left is pink, and the piece of paper on the right is green. 11 dominoes are scattered over the paper.]

### Speaker

Hello, little mathematicians! Today I've been playing with some dominoes and I have noticed some things. Firstly, I noticed that these representations of dots look really familiar to me. Can you think of where I might have seen them before? Yes, you're right. The dots are arranged in the same way we see on a dice.

[The speaker grabs a domino. One side has 4 dots, and the other side has 5 dots. The speaker covers the left side, which has 5 dots.]

### Speaker

Look, if I cover this side of the domino, I can see a spatial pattern of dots representing the quantity four…

[The speaker grabs a dice and places it, with its 4-face facing up, beside the domino. The arrangement of the dots on the domino matches the arrangement of the dots on the dice.]

### Speaker

..which is the same spatial pattern that we see on a dice here.

[The speaker covers the right side of the domino, which has 4 dots, and reveals the left side with 5 dots. She rotates the dice so that the 5-face is facing upward. The arrangement of the dots on the dice and dominoes match.]

### Speaker

And if I cover the other side of the domino, I can see a spatial pattern of dots representing five, which I can also see on a dice.

Now, I also noticed that some dominoes have the same quantity or amount of dots on each side and some don't.

[The speaker grabs a domino that has 2 dots on both sides.]

### Speaker

On this domino, I can see that there are two dots on this side, and two dots on this side. Both are equivalent, which means they are the same in value. And we call this a double.

[The speaker isolates the domino with 5 dots on one side and 4 dots on the other. She points to the dot in the centre of the arrangement of 5 dots.]

### Speaker

Let's zoom in on this domino. Yes you're right, mathematicians. On this side of the domino there is one extra dot in the middle. So each side is not the same, it is a not-double.

So now that we know what a double and a not-double is, I thought we'd investigate which of my dominoes were doubles and which of them were not-doubles, by sorting them into two groups.

[On the pink sheet of paper, the speaker lays a slip of paper which has the text, “Doubles”.]

### Speaker

On this side, I'm going to place the dominoes which are doubles.

[On the green sheet of paper, the speaker lays a slip of paper which has the text, “Not doubles”. She moves the dominoes to the bottom of the paper.]

### Speaker

And on this side, I'm going to place the dominoes which are not doubles.

[The speaker places a domino along the line that separates the two sheets of paper. One side has 6 dots, and the other side has 2 dots.]

### Speaker

What do you notice about this one? Yes you're right, mathematicians. There are less dots on this side so they are not the same, it is not a double.

[The speaker moves the domino to the “Not doubles” sheet of paper. She moves another domino to the middle of the two sheets of paper. Both sides of the domino have 4 dots. Te speaker points to each of the dots on both sides of the domino.]

### Speaker

Aha, I see that too! There is one dot in each corner on this side and one dot in each corner on this side. So they are the same, which means they are a double.

[The speaker moves the domino to the “Doubles” sheet of paper. She places another domino in the middle of the sheets of paper. Both sides of the domino have 2 dots.]

### Speaker

What do you think? Double or not-double? Yes, I see that too. They are the same on each side, it is a double.

[The speaker moves the domino to the “Doubles” sheet of paper. She places a domino in the middle of the sheets of paper. One side has 5 dots, and the other side has 4 dots.]

### Speaker

Aha, yes. On this side, there is one extra dot in the middle, which means they are not the same, so it is not a double.

[The speaker moves the domino to the “Not doubles” sheet of paper. She places another domino in the middle of the sheets of paper. One side has 3 dots, and the other side has one dot.]

### Speaker

What about this one? Yes, there are more dots on this side, they are not the same. So it is not a double.

[The speaker moves the domino to the “Not doubles” sheet of paper. She places another domino in the middle of the sheets of paper. Both sides of the domino have 6 dots.]

### Speaker

Aha, they are the same! I see that too. It is a double.

[The speaker moves the domino to the “Doubles” sheet of paper.

Text over a blue background: Over to you!]

### Speaker

Over to you, mathematicians!

[Text: Draw and sort these dominoes into doubles and NOT doubles. On image to the right of the text shows the two sheets of paper, with the headings “Doubles” and “Not doubles”. Each heading has 3 dominoes beneath it. Below that, are 8 more dominoes. The first has one dot and 4 dots. The second has 3 dots on both sides. The third domino has 3 dots and 6 dots. The fourth has 5 dots on both sides. The fifth domino has 5 dots and one dot. The sixth has 3 dots and 2 dots. The seventh domino has 5 dots and no dots. The eighth has one dot on both sides.]

### Speaker

Draw and sort the rest of my dominoes into doubles and not-doubles. Then come on back and we'll talk about what's next.

[Over a grey background, the red waratah of the NSW Government logo appears amongst red, white and blue circles. Text: Copyright State of New South Wales (Department of Education), 2021.]

[End of transcript]

## Instructions

Think about how you would sort these dominoes into doubles and NOT doubles.

## Watch

When you're ready, watch the next video Double hunt part 2 (2:35).

Draw a table and explore doubles around the environment.

### Transcript of Double hunt part 2

(Duration: 2 minutes and 35 seconds)

[Two sheets of coloured paper placed on a tabletop. On the left is a pink sheet of paper that has a small white rectangular piece of paper at the top with ‘Doubles’ written in black pen on it. Below it, 6 dominos are positioned that have the same number on each half. On the right is a green sheet of paper that has a white piece of paper at the top with ‘Not doubles’ written on it. 6 dominos are also positioned below that have different numbers on each half.]

### Female speaker

Welcome back, little mathematicians. How did you go sorting your dominoes? Well done. I sorted my dominoes like this. So, now that I know what a ‘double’ and a ‘not double’ looks like on a domino, I'm wondering where else I can find doubles in my home. So, let's go on a double hunt and see what we can find.

But I'm wondering, what is a good way to gather and record my ideas? I know. I'll draw a table.

[A blank sheet of white paper is placed down across the coloured paper. A purple marker is used to make a border around the outside and a line down the middle divides the page in half. On the left side ‘Double’ is written at the top and on the right side ‘Not doubles’. A line is drawn horizontally to underline both words.]

[Later, the sheet of paper has 3 drawings on each half. On the ‘Doubles’ side there is a drawing of some feet, a carton of eggs and a chest of drawers. On the ‘Not doubles’ side there is a drawing of a fan, desk drawers and a light switch.]

### Female speaker

I've just been on a double hunt around my home and this is what I found.

[Colour images appear alongside the relevant drawing when mentioned.]

### Female speaker

I first found double 6 in a carton of eggs. Next, I found double 1 in my feet. After that, I found double 4 in a chest of drawers. The not doubles I found were a fan which had 3 propellers, a light switch with just one button, and finally, a desk that had 3 drawers.

[White text on blue reads ‘Over to you!’]

### Female speaker

Over to you, little mathematicians, to go on a double hunt around your home and find 3 examples of doubles and 3 examples of not doubles. Have fun.

[White text on a blue background reads ‘What’s (some of) the mathematics?’]

### Female speaker

So, what's some of the mathematics we explored today?

[A blue text header on a white background reads ‘What’s (some of) the mathematics?’ Three bullet points below (as read by speaker). On the right, two colour images of the pink paper and dominoes ‘Doubles’ side in one image and the green paper ‘Not doubles’ side and dominoes in the other.]

### Female speaker

When we are combining two groups that are the same size, which means they are equal, we can call them a double. We can also use the words “twice as many” to describe a double. When we are combining two groups that are not the same size, so they are not equal, they are not doubles.

[An additional bullet point (as read by speaker). Below, a colour image of the ‘Doubles’ and Not doubles’ drawings from earlier alongside their respective colour images.]

### Female speaker

We can find doubles and not doubles in our houses, gardens, schools, and in the shops. They are everywhere.

[An additional bullet point (as read by speaker). Below, the sheet of ‘Doubles’ and ‘Not doubles’ drawings without the colour images.]

### Female speaker

Tables are really useful to gather and record information.

[The NSW Government waratah logo turns briefly in the middle of various circles coloured blue, red, white and black. A copyright symbol and small blue text below it reads ‘State of New South Wales (Department of Education), 2021.’]

[End of transcript]

## Instructions

• Draw a table, like the one below.

• Go on a doubles hunt! Can you draw 3 examples of doubles and 3 NOT doubles?