Lesson video

Hello my name's Miss Robson in this lesson, we are going to be investigating one more and one less of numbers within 10.

We're going to start by investigating one more and one less of different numbers using cubes.

Then we're going to look at one more and one less on a number line.

Finally, it'll be your turn to have a go at investigating one more and one less before we play a game of Guess How Many.

For this lesson you'll need a number line to 10 and you'll need at least 10 things in one colour and just one thing in another colour.

So I have orange cubes and lots of them and just one blue cube.

Pause the video here to collect the resources that you need and when you're ready press play.

When we find one more and one less of a number, what we're doing is we are either adding one or taking one away to find out how many there are.

So if I have the number one, two, three, four, five, six, I've got six orange cubes here, I can add one to make seven, six and one more is seven.

One more than six is seven.

If I have the number six and I'm taking one away, one less than six is five, six, take away one is five.

We can look at them like stairs, if you look at the multicoloured cubes, the purple, orange, green, red, and yellow cubes, they look a bit like stairs and we can either walk up the stairs or we can walk back down the stairs.

So sometimes I like to do this with my hands to remember that I'm either adding one more or taking one away.

So walking up the stairs or walking back down the stairs, if you look at the green at tower, the green tower has four cubes.

One more than four is five, if we take one step up to the red step, there are five cubes in that tower.

We take one step back down from the green tower, we get to the orange tower, which has three cubes.

So, if I have four cubes Like the green tower, one more is five and one less is three.

Can you get your cubes or manipulatives whatever it is that you gathered earlier and can you make a tower of five? I have my tower of five ready.

One, two, three, four, five with your other coloured thing, whether that's a cube or a bead, whatever it was that you found.

Can you add that on top to find out what one more than five is.

You might need to, you can count on if you need to, so five and one more five, and one more is, six.

One more than five is six, take away that cube of a different colour or item of a different colour.

Now we should be back to five, take away one from the top.

One less than five is, one less than five is four.

We can use this method of adding one and taking one away with our manipulatives to work out one more and one less, but we can also do it in our heads.

You can see these yellow tablets here are a bit like what we were just doing, where you have your towers in one colour, so these ones are in yellow, one, two, three, four, five, six, seven, just like this one here, seven cubes and then we've added that extra cube on top in a different colour to make it really obvious that these towers are the same height and I just added one more, one more than seven is eight.

If I were to get rid of one of these cubes from the top, if I were to take it away, let me build my tower of seven four, five, six, seven, I've got my tower seven, one, two, three, four, five, six, seven and I take away one, how many will I be left with? One less than seven is six.

Excellent, if at any point during today's lesson, you get stuck and you can't figure out what one more or one less is, you can get your manipulatives back out again and you can make the tower and either add one in a different colour so that you can see one more or you can take one away from your tower to figure out one less.

We're now got to look at this on a number line.

So what we've done is we have our cubes and we've turned them onto the side and you the a number line on top.

So we have both representations next to each other in case we need them.

First, we're going to think about what one more and one less of one are, popping the number one in your head or putting your finger on the screen on the number one, one more than one is, we just jumped one over.

One more than one is two, can you copy after me? One more than one is two.

Jumping back to the other way, one less than one is zero your turn.

Fantastic, what we've done with our number line is we've drawn some arrows to show us one more and one less, we're just hoping one more along the number line or one less backwards or if you're looking at cubes, one more than one, or I start with this side.

One more than one is two or one less than one is zero.

So you can use the cubes like this, like a number line as well to help you.

Now we're going to be thinking about the number nine so can you find the number nine on the number line? What is one more than nine? Can you put it in a full sentence? One more than nine is 10.

Excellent, so what would one less than nine be? In a full sentence.

One less than nine is eight.

Let's check.

There are arrows jumping one more or one less and again remember, you've got your cubes in front of you, you could use them to jump on and back to.

When we find one more, we're just counting one more on or adding one more on and when we're finding one less, we're taking one away.

So your task for today is to be in a maths investigator or a mathematician.

What you're going to do is you're going to pick any of the numbers on the number line below and investigate what one more and one less is.

First, you need to make it using your cubes, then you can either draw or just use your finger to do the jumps on the number line.

And you need to use your full sentences to describe what one more and one less is.

So, let me show you an example, I'm going to start with the number three.

So here are my three cubes, one, two, three and then I get my different coloured cube, one more than three is four, then I go back to three, one less than three is two.

One less than three is two.

What I then do is grab my pointer and I find the number three, here it is.

One more than three is four, one more than three is four, one less than three is two, one less than three is two.

You can choose numbers by, I like to close my eyes and move my mouse around and pick one.

I'm going to try the number five next, so let's try that one, here's five, one more than five is six.

One more than five is six and one less than five is four, one less than five is four.

You can either do that and choose numbers at random or you could just work your way along the number line, I think it's more fun just to pick random numbers though.

This task is going to really help you with your understanding of numbers to 10.

Because when you know one more and one less, you be able to apply that skill later on to addition, subtraction and lots of other things.

It's time now for you to complete your task, so you need your number line to 10, you need your objects that you can use to make one more and one less, and you need to do some really good investigating to find out what one more and one less of all of the numbers up to 10 are.

Pause the video here to complete your task when you're finished, press play.

I hope you've enjoyed investigating one more and one less of numbers within 10, we have a game to play now to finish us off that's called Guess How Many.

This girl here is, there's a speech bubble by her head and she is posing us, she's giving us some clues as to what number she is thinking of.

So let me read you her clues and I'd like you to have a go at working out, what's that's with your number line or with your cubes, what number is inside of her head.

Are you ready? She says, I have fewer than eight, but more than six, I have fewer than eight cubes but more than six, pause the video here to look at your number line or use your cubes and have a go at working out what the answer is.

So she has fewer than eight, I had to get my eight cubes, one, two, three, four, five, six, seven, eight, here's eight, so she has less than eight, so less than this, fewer than this, but more than six.

So if I get one, two, three, four, five, six, so more than six, but less than eight, one, two, three, four five, six, seven, seven is more than eight.

Seven is more than six, but it is one less than eight.

Seven is the number that is in between eight and six.

You can find it on your number line and you will see that seven is in between eight and six.

That was a little bit tricky, wasn't it? You can play this game with your talk partner, parent or carer and you can think of a number and describe to them what one more or one less of that number is and see if they can guess what number you're thinking of.

Thank you for joining me today for our investigation into one more and one less.

I hope that you've enjoyed yourself as much as I have, you've done some fantastic learning.

Why not share your work with us? If you'd like to, please ask your parent or carer to share your work on Twitter, by tagging @OakNational and using the #LearnwithOak.

We'd love to see what you've been getting up to.

Don't forget to go and complete the quiz.

Thanks again and see you next time.