Lesson video

Hello, my name is Miss Robson.

In this lesson, we're going to be exploring one more and one less of numbers beyond 20.

We're first going to look at the Hey Diddle Diddle picture to remember some quantities that we've counted in the past and find one more and one less of those, then we're going to use a number track to figure out one more and one less and finally, we're going to have a go at investigating one more and one less of some different numbers and recording them.

For this lesson, you will need a number track, preferably one that goes all the way to 50 to support you with your one more and one less.

We're going to start by looking at our Hey Diddle Diddle picture and using some of the things that we've counted in the previous lessons to set some stories for us, for our one more one less.

So, I remember that there were 20 trees all together.

There were 10 on one side of the hill and 10 on the other side of the hill, all together there were 20.

One day, somebody came along and decided that they were going to plant one more tree.

One more than 20 is 21.

Can you say that full sentence with me? One more than 20 is 21, fantastic.

Every time we say one more or one less than a number, we have to make sure we put it in a full sentence.

In the starry sky there are 40 stars all together.

Remember we found four lots of 10, four different groups and each group had 10 stars in it.

So, 40 stars all together in the sky, but one night the sky was quite cloudy and we could see one less star.

One less than 40 is 39.

Can you say that full sentence? One less than 40 is 39.

So, when we could see one less star, we could only see 39 stars all together.

Now, it's your turn to have a go.

In the village, all of the houses have windows.

All together, all of the houses combined have 23 windows.

So, 23 windows in the village.

One day, someone decides that their bedroom is a bit too dark and so they decide to put in an extra window.

So, what is one more than 23? You can use your number track to help you if you like or you can try using your head and counting on one more, one more than 23.

Did you put it in a full sentence? One more than 23 is 24.

Fantastic, well done.

Here is our number track, it is inside the cow that was jumping over the moon.

So, let me get my pointer and we're going to have a go at tell you some more, one more, one less.

So, let's start with the number 26.

When we're saying one more, we are adding one more and when we're saying one less, we're taking away one.

It's like counting up one or counting back one from that number.

26, I had 26 hoops to play with and then one of my friends asked if they could borrow one and I said, of course and I gave them one of my hoops.

One less than 26 is 25.

I had 26 hoops and I gave one away, now I have 25.

If I had 26 balls and one of my friends came to give me another one to see how many we could have all together.

One more than 26 is 27.

I had 26, I added one more, now I have 27.

Every time we say one more or one less, we need to make sure that we use a full sentence.

So, one more than 26 is 27.

One more than 26 is 27, fantastic and one less than 26 is 25.

One less than 26 is 25, excellent.

I'm going to ask you another question and this time it's your turn to give me the full answer.

So, you have 35 apples.

Here's the number 35.

You have 35 apples and one of your friends comes and asks for one of them.

What is one less than 35? Put it in a full sentence.

One less than 35 is 34.

Your turn, one less than 35 is 34.

Fantastic, well done.

This time there are 46 bananas and a monkey comes and gives you one more.

What is one more than 46? One more than 46 is 47.

Remember, if you need to, you can use your finger on the screen to bounce on or bounce back.

One more than 46 is 47, fantastic.

You can use a number track to help you if you like or you can count on or back one in your head, whichever one works for you.

Your task is going to be to record one more and one less.

On the screen, you can see a table.

Over here it says one less, over here it says one more and in the middle is our number.

So, here's the number 23.

One more than 23.

One more than 23 is 24.

So, over here I would write the number 24.

23, one less and 23.

So, I'm climbing back down my ladder.

One less than 23 is 22.

One less than 23 is 22.

So, in this side over here, I would write the number 22 and in this side over here, I would write the number 24.

Just like this, 23 is the number that I was looking to start with and I'm going to find one less than 23 and one more than 23.

So, I've recorded that one less than 23 is 22 and one more than 23 is 24.

You're going to have a go at exploring some different numbers and recording one more and one less in a table like this.

I've given you a few numbers to investigate.

You can use a number track, a number line, you can use a bead string if you have one or some cubes, anything that you think might help you to figure out what one more and one less of each number is.

If you know them just by counting on and back in your head, that's fantastic and you can just write them down on the paper.

When you're finished, take a sit back and have a look at the answers that you have for one more and one less and think about if you can see any patterns or maybe if you notice something about the numbers.

It's time now for you to pause the video and complete your task.

When you're finished, press play.

So, these were the numbers that you were investigating.

You were looking for one more and one less than 34, 46, 29 and 40.

I used my bead string to help me for one of them and I used my counting on and counting back in my head skill for the others.

So, one more than 34, 34, 35.

One more than the 34 is 35.

One more than 46, 46, 47.

One more than 46 is 47.

One more than 29.

This was the one that I needed to use my bead string for.

So, I've got 10, 20, 29.

So, 10, 20, 10, 20, 29 and one more.

One more than 29 is 30.

So, now I've got 10, 20, 30.

One more than 29 is 30 and I had 40 and one more than 40 is 41.

Let's check those answers.

There you go.

Then, I thought about working back.

So, one less than 34 is 33, one less than 46 is 45, one less than 29 is 28 and one less than 40.

Now, this one I had to use my cubes for.

So, here are my cubes and I've got 10, 20, 30, 40 and one less.

So, what I just do.

Oh, just take one away.

So then, I've got 10, 20, 30, 39, one less than 40 is 39.

There you go.

If you're interested in one more and one less, you can continue investigating in your everyday life.

When you pour a bowl of cereal, you could count how many there are or estimates and imagine adding one more or eating just one and finding out what one more or one less would be of how many are in there all together.

You could count how many books you have or how many toys you have and imagine having one more or giving one away to find out what one less would be.

There are lots of ways for us to practise one more and one less.

I hope you've enjoyed joining me today to investigate one more and one less.

Why not share your work with us? If you'd like to please ask your parents 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.

Thanks again for joining me.

See you next time.