Subitising (more, less, same)
A thinking mathematically targeted teaching opportunity focussed on building relationships using the language of more, less or the same
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, 2021
Be ready to work out what quantities are more, less or the same. Watch Subitising – more, less, same video (6:08).
Welcome back young mathematicians.
We're gonna play around with some ideas more, less, or same.
[Screen shows 2 A4 pieces of paper, laid side-by-side. The page on the left is pink and the page on the right is black. In the middle of the 2 pages at the top it reads ‘More, less, same’.]
I'm going to show you two different collections and I'd like you to think about, which one is more, or which one has less or are they the same?
So, let's have a go. Here come your first 2 collections.
[Presenter lays down 2 ten-frames, one on each piece of paper. The ten-frame on the left is full and shows 10 dots and the one on the right has one dot.]
Which one has more? That's right, it is this one, isn't it? And I think you can tell that it has more without even counting.
[Presenter points to the left ten frame.]
You can use your skills in visual recognition and subitising because look, this one has dots in every box and this one has a dot in one box. So, this one has to be more, which means this one has to be less.
[Presenter points to the left ten-frame indicating more and then the right ten-frame indicating less.]
Ok, let's try another one. Are you ready? What about this time? Here we go.
[Presenter places 5 block cubes on the left side and one teddy counter on the right side.]
Which one has more? This one. Which one has less? This one.
[Presenter points to the left side indicating more and then the right side indicating less.]
Are they the same? No. And I don't actually have to count this one either because I can see this would correspond to that block.
This teddy would match this block and then I have all of these other one’s leftover that don't have a matching pair.
[Presenter moves one cube and the teddy next to each other on the edge of the pages in the middle and moves the other 4 cubes down the page.]
So, I know this is more and this has less. Ok, let's try another one.
[Presenter points to the group of cubes and then the teddy, then removes all objects.]
Are you ready? Ok, here we go. Oh.
[Presenter places 2 full ten-frames, showing 20 dots, on the left side and one ten-frame with 4 dots on the right side.]
Yes, that's right. This one has more and this one has less.
[Presenter points to the 2 ten-frames on the left indicating more and then the right side indicating less.]
And again, we don't have to count because we can see here that that's one, ten-frame and it's not full, but over here there's 2 ten-frames and both of them are full.
That's right, so this must have more, which means this one has less.
Ok, let's try another one. Are you ready? Here we go. What about now?
[Presenter places one teddy counter on the left side and 3 on the right side.]
Which one has more? This side. Which one has less?
[Presenter points to the 3 teddies on the right side indicating more and then the one teddy on the left side indicating less.]
Yes, and are they the same? Not yet. We haven't found any that are the same yet.
Ok, let's try another one.
[Presenter removes teddies.]
Here we go. Ready? Which one has more?
[Presenter places 3 yellow teddies on the left and 2 red and one yellow teddy on the right.]
Haha, which one has less? You're right, this time it's the same. So, I can line them up. These ones have a pair that match. These ones match and this one matches.
[Presenter lines up a teddy from each piece of paper in the middle into 3 rows of 2.]
So, they both have the same amount, and I could count to check as well. Look.1, 2, 3 like a triangle and 1, 2, 3 like a dice.
[Presenter moves the 3 teddies on the left into a triangle and the 3 teddies on the right like a dice pattern. Presenter removes the teddies.]
They both have the same because they both have 3.
Ok, let's try another one. Here we go. Ready?
[Presenter places 3 yellow teddies on the left side and a collection of 4 green, 2 yellow, 2 red and one blue teddy on the right side.]
Which one has more? Yes, this side isn't it and which one has less?
[Presenter points to the right side indicating more and then the left side indicating less.]
This one. And are they the same? No, you're right, they can't be because this is more, and this is less.
[Presenter’s hands touch the 9 teddies on the right side indicating more, then touch the 3 teddies on the left side indicating less again.]
They can't be the same. And, actually what we're using here is we're subitising aren't we? To see which one has more and which one has less.
We could be more precise. Would you like to do that? And we can count them to see how many? Ok, let's try that.
So, 1, 2, 3 like a triangle and on this side. Ok. 1, 2, 3, 4, 5, 6, 7, 8, 9 bears. This side has 3 bears, which is less than 9 bears.
[Presenter moves the 3 teddies on the left into a triangle. The presenter counts as they move the teddies on the right into 4 rows based on colour. There are 4 green teddies in the top row, 1 blue in the next row, 2 red in the next row and 2 yellow in the bottom row. Altogether there are 9 bears. Presenter points to the left side indicating less, then the right side indicating more.]
Ok, let's try one more little mathematicians. See what happens? Are you ready? Ok. Are they more, less or the same?
[Presenter places 2 plates on each piece of paper. The plate on the left has 3 red and 3 orange pom poms, and the plate on the right has 4 orange, one green and one red pom pom.]
Oh, you're having to count aren't you? Yeah, 'cause it's so close, it's hard to tell. Should we count them together, and see?
Ok, so over here I can see 3 and 3, and I actually, I know three and 3 is 6 because I've learned that by looking at dice patterns.
That when I have 3 on one side and 3 on the other side, that looks like a dice.
[Presenter circles the 3 red and 3 orange pom poms on the left with their finger.]
And on this side, I can see three and two and one.
[Presenter points to the 3 pom poms in a line, then the next 2 and then the last one.]
Let's count. So, 3, 4, 5, 6. And on this side.
3, 4, 5, 6 or 1, 2, 3, 4, 5, 6. 1, 2, 3, 4, 5, 6. So this side has 6 and this side has 6.
[Presenter points with finger and counts the pom poms on each plate. They circle the pom poms on each plate with their finger to indicate that each side has 6 pom poms.]
So, they have to be the same. Nice work mathematicians. That one was tricky.
[Presenter points to the top of the pages where it reads ‘more, less, same’ and highlights ‘same’.]
So, what was the mathematics we were just playing with? Well, we used our skills of subitising this time to talk about and determine some really important relationships, like more, less and the same.
And what you might have noticed is that when the collections got really big or, or one of the collections got really big, or when the collections were really close together or the same, it was sometimes really hard to work out more, less the same, just through subitising.
So, we had to use other skills to help us work that out.
Nice work today, little mathematicians.
[End of transcript]
Follow along with the video, listening and watching carefully.
Be ready to work out which quantities are more, less or the same.