Ordering numbers within 100

Key Stage 1

Maths

Numbers within 100

Look at the 2-digit numbers below. Which sign is needed in the blank space?

Look at the 2-digit numbers below. Which sign is needed is the blank space?

Which of the number sentences below is incorrect?

﻿Hello everybody, and welcome to today's math session. My name is Miss Hughes, and today we're going to be looking at comparing and ordering two digit numbers within 100. We're going to be looking at how we can order these numbers in increasing and decreasing order. So let's get started. For our lesson today, you're going to need a pencil and rubber, some paper, and you will need some countable objects to represent tens and ones. You can use pastel, counters, marbles, Lego, just make sure you ask an adult at home before you go and get these things. If you don't think you have any countable objects at home, you can always draw out your tens and ones. Please pause the video now, let's go and get these things if you haven't got them already. Brilliant. Let's have a look at our lesson agenda for today then. We're going to start off by looking at numbers in increasing and decreasing order. Then it's your talk task. Next, we will be placing numbers in increasing and decreasing order ourselves, then you'll have an independent task and we'll go through the answers. And finally, you have your quiz at the end to recap everything you've learned and see just how much you've remembered from today's lesson. Let's start our lesson of today, we're going to look at this image of the market stall on the slide. And I want you to think about this question that's in the bubble. Are there more or fewer oranges than apples at this market stall? And how do you know? I'll give you a little bit of time to think about it and then we'll talk about it together. Well, you've probably noticed just by looking at the picture that there are a lot more apples than oranges. But let's double check this by counting them. I'll start with the apples first. I have four hundreds, eight tens here, and seven ones. Now for the oranges, I have one hundred, three tens and five ones. Let's represent that in a place value chart so we can see these numbers really clearly and visually. So here's my first place value chart. So for my apples, I have four hundreds, 100, 200, 300, 400. Eight tens, 410, 420, 430, 440, 450, 460, 470, 480. And seven ones, 481, 482, 483, 484, 485, 486, 487. Wow, that's a lot of apples, 487 apples. Now, let's represent our oranges. So I have 100, there it is. Three tens, so 110, 120, 130, and five ones, 131, 132, 133, 134, 135. Okay. So now I have represented my numbers, I can clearly see which is the greater number. Starting by looking at my hundreds, I remember we always look at the digit with the highest tally first. I'm looking at my hundreds. There are more apples than oranges because 400 is greater than 100. There are more apples than oranges. There are fewer oranges than apples. Let's imagine now that five customers went to buy some apples at the market, and they all bought different numbers of apples. Here are the amounts of apples that each customer bought. For each of these amounts, I want us to think about this question. How have the numbers been ordered? The numbers are one, two, six, 20, and 25. To help us answer this question, I'm going to represent these numbers in place value charts so we can see our numbers really clearly. So here are my place value charts. And obviously, to represent one that is worth one, one. So I'm going to put a one in the ones column. To represent the number two which has the value of two, I need two ones. To represent six which has the value of six, I need six ones. To represent 20, remember that is two tens and no ones. And to represent 25, I've got to tens, 10,20, and five ones, 21, 22, 23, 24, 25. So looking at our representations, I can see we start with one, one here. Next we have two ones, which is greater than just one. Then we've got six ones, which is greater than two. Then we've got two tens, which represents 20 and that's greater than six. And 25 is greater than 20, 20 is less than 25. So 25 is the greatest number that we have here. So I think that all the numbers are getting bigger. In other words, they are increasing because we start with our lowest value number and then each time the value increases. Let's practise that word increasing with a my turn your turn. So my turn, increasing. Your turn? Fantastic job. Well done, guys. Let's look at a new one together. The numbers are 24, 23, 22, 21, 20. I want to think about what, or how these numbers have been ordered. So I'm going to start by representing them with tens. So here are my place value charts. 24 has two tens and four ones. 23 has two tens and three ones. 22 has two ones, sorry, two tens and two ones. 21 has two tens and one one, and 20 has two tens and no ones. So all of my numbers have an equal number of tens. They all have two tens. So to compare them, I need to look at the ones now. So let's have a look. I've got four ones here, three ones here, two ones here, one one here, and zero ones here. Okay. So I think the numbers are actually decreasing because 24 is the biggest number, is the greatest number. I know it's the greatest number because it's got the largest number of ones compared to all the other numbers. 20, on the other hand, is the smallest number with no ones. And as we look along the row of our numbers, each time, the ones are getting one less. When numbers are getting less and less, we say that they are decreasing. Let's practise that word together, my turn, decreasing. Your turn? Excellent. Just like we did in our new learning for your talk task, you're going to look at a group of numbers and decide if they are ordered in increasing or decreasing order. You will need some countable objects to represent your tens and ones for this task. Or you could always draw out your tens and ones. Here are a couple of examples of how you could represent a number with different objects. I have used, oh, sorry, I've represented the number 12 using pastel. So here I've got one 10 and two ones to represent 10, 11, 12. And I've also just done a drawing. So I've drawn out my tens and ones. So I've got one 10, which is 10 and two ones, 11, 12. So while you're completing your talk task, you can represent your numbers in these ways. Once you've made each number, I want you to use these sentence stems to help you to explain whether the numbers are in increasing or decreasing order. Pause the video now to have a go at this task and play the video when you're ready to resume. Right team, let's have a look at these then. So I'm going to use these sentence structures to help me explain whether these numbers are in increasing or decreasing order. So the numbers are four, five, eight, 19 and 91. I think the numbers are increasing because four is the smallest number and 91 is the greatest number, and each number gets larger. I know this because four, five and eight all have no tens, 19 has one 10 and 91 has the most tens. It has nine tens. Let's now look at this next group. The numbers are two, 23, 69, 70, and 71. I think the numbers have been ordered in an increasing order because two is the smallest number and each number gets larger. Two has no tens, 23 has two tens, 69 has six tens. So these numbers are getting greater, and 71 is the greatest because 71 has seven tens. Now that we know how to identify if numbers are in increasing or decreasing order, it's now going to be your turn to put numbers in order. So, if you look at this slide, you will see four representations of different numbers, and we want them to be put into increasing order. So the first thing I need to do is figure out what numbers I have here. I'm going to give you a few seconds to think about what number each of these images is representing. Okay, have you figured out what numbers they are? Brilliant. Okay, so in this first image, I have four tens and one one. Let's count them. 10, 20, 30, 40, 41. So this represents 41. Here I have eight tens and four ones, sorry, eight tens and one one. Let's count those. 10, 20, sorry, 10, 20, 30, 40, 50, 60, 70, 80, 81. So this image represents 81. This next image I have one, two, three, four tens and four ones. So that's 10, 20, 30, 40, 41, 42, 43, 44. So this represents the number 44. And then the final image, I have one 10 and four ones. 10, 11, 12, 13, 14. Now, we are ordering these numbers in increasing order. Will the first number or last number in this order be the greatest? Have a think about that question now and think about how you know. I'm going to give you a few seconds first. Which number, the first or last, will be greatest if we're putting on numbers in increasing order? Let's see if you thought the same as me. I know that increasing means the numbers are getting larger or my numbers are getting greater. So because we are ordering these numbers in increasing order, they'll be getting bigger each time. That means that the greatest number will need to be last and the smallest number will need to come first. So which is my smallest number of all of these then? Well, I can see that 14 only has one 10. And that is the smallest number of tens of all of my numbers. So that is my smallest number. Let's move that to the front. Great. Now, I need to find which number is the next smallest out of 41, 81, and 44. Well, 41 and 44 both have four tens which is less than eight tens. So it's going to be between those two. Since they both have the same number of tens, I need to look at the ones now, to compare them. 41 has less ones than 44. So this must be the next smallest. From looking at the numbers I've got left and from looking at the tens I can see that 81 is the greatest and so that needs to go at the end, which means 44 must go next in my sequence. And voila, our numbers are now all in increasing order. They are all getting bigger. Here are four more representations of numbers and we want to put them in decreasing order. So the first thing we need to do is identify which number these images are representing. The first one is 45. The next one is 71. Then 54, and finally, this last one is representing six because there are just six ones. So they each have a value of one, one, two, three, four, five, six. Brilliant. Now that we know which numbers are being represented, we can start to think about ordering them. Now, we are ordering these numbers in decreasing order. So will the first number or the last number be the greatest in this sequence? What do you think? Take a few seconds to think about that now. Let's see if we think the same thing. So I know that decreasing, this word decreasing means that numbers will be getting smaller. So because we are ordering these numbers in decreasing order, they will be getting smaller and smaller and smaller each time. So the smallest number needs to be at the end, that means the greatest number will need to be first. So which is my greatest number of these ones? I can see straightaway that 71 has the most number of tens. So that is the largest or greatest number, and will need to go first. Now, we need to find which number is the next greatest out of 45, 54 and six. Well, six has no tens so that is definitely the smallest number. 54 has five tens and 45 only has four tens. Therefore, 54 is greater. So that will go next. Then it will be 45 because it's much larger than six. And finally, six will go at the end as it is the smallest. Now, all of my numbers are in decreasing order. They are getting smaller. Right team, now, it's your turn. This is your independent task for today. So you've been given different representations of different numbers in tens, just like we saw in our Develop Learning Tasks. You need to order these numbers in increasing, so in some cases, it's increasing or decreasing order And it tells you which one on the sheet. So you're going to need to figure out what number each of these images represents and then write the digits in the correct order in the boxes below. Pause the video now to complete your task and resume once you're finished. Excellent job, team. Let's go through those answers now. So in the very first instance, you needed to put your numbers in increasing order. So you should have started with 20, 22, 32, and the greatest number 33. The next set of images you needed to put in decreasing order. So you should have started with the greatest number first, which was 62, 26, 10 and two. Next, you're putting your numbers in decreasing order. So again, starting with the greatest first, which was 73, 43, 30, and 13. And lastly, you had to put your numbers in increasing order. So you needed to start with the smallest first and end with the greatest. So you should have started with 17, then 70, then 76, and then 80. Well done if you got all of those correct. Excellent job. Well done, everybody. We've now reached the end of our lesson and I wanted to say a huge well done for all of your hard work. I think you did a fantastic job of ordering numbers in increasing and decreasing order. So now, all that's left for you to do is take part in the quiz and see how much you can remember from today's lesson. Hopefully, see you very soon on another session. Bye-bye. If you'd like to, please ask your parent or carer to share your work on Instagram, Facebook or Twitter, tagging @OakNational and #LearnwithOak.

Ordering numbers within 100

Ordering numbers within 100

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UnitMaths / Numbers within 100

Maths