Video: Finding one less than a given number

﻿Hello, everyone. It's great to see you. I was just getting my teddies ready for their Teddy tea party. Do you want to see all the guests that have arrived already? Let's take a look. You've got snail, fox, duck, elephant, and a few more. Actually, 10 guests have arrived already. There are 20 teddy guests that have been invited to the Teddy tea party , but 10 guests have arrived already. How many guests are we waiting for? Do you are know? Shout the answer out to the screen if you do. Great. I can hear some of you say the answer. 10! We're waiting for 10 teddy guests. 10 add 10 makes 20. Well done everyone, that was working out. Now, we're going to have some ice cream at the Teddy tea party. And I've got some spoons for the teddies to have their ice cream. But I'm not quite sure if I've got enough. If there are going to be 20 teddy guests, how many spoons do I need? Shout the answer out. Great. 20. You can help me count spoons? See if I'm going to have enough. You can count with me. One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. I have 19 spoons. If I'm going to have 20 teddy bear guests. How many spoons do I need? I can hear some of you saying the answer. Let's have a look and see if we can use the number line to help us. Here's the number line. So we count it together. I have 19 spoons, but I'm going to have 20 teddy bear guests. How many more spoons do I need? Let's see if we can use our fingers to help us work this out. So 19 spades I've got already. But I need 20 for my 20 guests. We're going to do one jump to get to 20. How many jumps? One jump. I need one more spoon. I'll pop to the shop later to see if I can pick that up. Out there, I wonder who that could be. Is there any other quest? Oh, it's Reggie. Hello Reggie, I didn't think you were coming to the party. Oh, Reggie says she's brought a special treat for some of the guests. Of course you can bring it up. Oh, here we are. What have you brought, Reggie? Reggie's brought some sweets for the guests. That's very, very kind of you. Thank you very much, Reggie. I'll share those out later. So for today's learning, we are learning one less than a number. You are going to need, a number grid that looks a little bit like this, and you are also going to need 20 small objects for counting that you can put onto your grid. Press pause to go and get those things now, and I'll see you in a bit when you are ready. Welcome back, everyone. Have you now got your number grid and your objects for counting? You do? You are now ready for today's learning. Let's take a look at some of our star words for today. You can say them with me as I point to them. One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. Those are our star words for today. So let's move on to our learning. So I'm going to choose a number grid here, and I'm going to put it here on the screen for you to see. Let's see if we can see all of those numbers all the way up to 20. There we are. Great. Shall we check to that they're all there. One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. That's the amount of guests that we're going to have at Teddy tea party. I've got an idea, let's see if I can count out 20 sweets for the guests. You can help me count them too. One, two, three, four, five, six, seven, eight, nine, 10. Oh, would they be enough? I hope so. 11, 12, 13, 14, 15, 16, 17, 18 19 20. They were just enough. Thank you Reggie, you brought just enough sweets for the 20 teddy quests that are going to be at the party. Thank you very much. Oh, I don't think you can have one Reggie, because that means that they won't be enough for the guests. Oh, but if you take one, they won't be enough. Hello there everyone, do you think we can check? There were 20 sweets here and there's one for all the 20 quests that we're going to have. If Reggie takes one, then they won't be enough. I don't think that Reggie can have one. Sorry Reggie. Anyway, so let's get back to our learning. There's a sweet missing. Oh dear! Reggie, do you know where it's gone? Oh, okay. Well, if we've got one sweet missing, how many sweets are left? Do you know? Let's take a look. We had 20 sweets. There is one sweet missing here. How many sweets are left? Shout the answer out to the screen if you know. 19. There are 19 sweets left. One less than 20 is 19. Can you say that? Great. One less than 20 is 19. Well, maybe I can pop to the shops a bit later and get another sweet. That's absolutely fine. Anyway, let's have a look again... Great. Huh, something keeps happening here. I've noticed that there is another sweet missing. Oh dear, how many sweets are left? Do you know? We had 19 and now there's one less. How many sweets have we got left? Shout me out the answer to the screen if you know. 18. One less than 19 is 18. Can you say that? Great. Let's take a look. There was 19 sweets but now we've got one less. Now there're 18 sweets left. We can count them just to make sure. One, two, three, four, five, six, ` seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18. I don't know what was happening with these sweets. Do you know what happened to the two that are missing? Well, maybe I can figure that out a bit later. You can practise taking one of your objects away from your number grid too. So, put your number grid in front of you and then put your 20 objects on top of your number grid, just like I did. Once you've done that you can practise taking one away and then finding out how many you have left. Practise that with a grown up and see what the answers that you get. Remember to use your careful counting too. Before you go, I was wondering if you could help me with a little help. So I've got some cards here, I'm going to chose one. Let's see. Here we are. Let's see the number. What number is it? 12. Great. I wonder if you can tell me what is one less than 12? Do you know? Shout the answer out to the screen if you do. Great. 11. One less than 12 is 11. Can you say that? Great work, everyone. You've done an amazing job today. Remember to keep practising one less than on your number grid and I'll see you again next time.

Lesson summary: Finding one less than a given number

In this lesson children will use a number grid and objects to find one less than a given number within 20.

Maths

Finding one less than a given number

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Lesson summary: Finding one less than a given number

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