What number do these strawberries represent?

Which bead string image represents the number line below?

The value of the digit 3 in my number is 3 ones.  My number is less than 45. The digit in the tens place is one less than 5. What is my number?

The value of the digit 4 in my number is 4 tens.  My number is less than 45. The digit in the ones place is one less than 2.  What is my number?

Representing 2-digit numbers (Part 1)

Key Stage 1

Maths

Numbers within 100

What multiple of ten do these Dienes represent?

Which part-whole model matches the Dienes representation below?

Here is a representation of the number 90. How many more tens are needed to make 100?

Here is a representation of the number 40. How many more tens are needed to make 100?

﻿Hello everybody, and welcome to today's session. My name is Miss Hughes, and I'm really excited to be teaching you about representing two-digit numbers today. So let's get going. For today's lesson, you are going to need a pencil, some paper and some countable objects. If you've got one, a number line to 100 will be really really useful today because we're going to be looking at two-digit numbers on a number line. Pause the video now and get the equipment that you need, if you've not got these things already. Fabulous. Let's have a look at our lesson agenda for today. So to start off with, our new learning is going to be looking at representing a two-digit number in different ways. And specifically, we're going to be learning how we can represent two-digit number on a number line. Then you're going to have a talk task that allows you to have a go at doing this yourself. As part of our developed learning, you're going to be thinking about identifying mystery numbers and then you're going to have a go at this yourself in an independent task, we'll of course go through the answers. And then finally you have your final quiz, where we can see all of the fantastic things that you have remembered from today's session. To begin our new learning today, I want you to look at the delicious strawberries that I bought this morning that are on the slide. I want to know how many strawberries I bought? Because I've already forgotten. I'm going to give you a little bit of time to see if you can figure it out for me. Have you got an answer? Let's see if that was the same. Hmm, well I can see that my strawberries are arranged in groups of 10, which makes them really simple to count because rather than counting them all individually, I can just count them in tens. So let's give that to go, 10, 20, 30, 40, 50, 60. I have 60 strawberries all together. I could represent my 60 strawberries on a bead string. And I want you to have a think about how we could do that. Hmm, well, because I've got six groups of 10 strawberries, I'm going to need six groups of 10 beads on a bead string to make 60. And that would look like this. let's count our 10, our sorry, our six groups of ten, one, two, three, four, five, six. So if I was to count in tens, that would be 10, 20, 30, 40, 50, 60. So just like my 60 strawberries that I have, I've got 60 beads that are laid out in six groups of ten. On my bead string, I can really clearly see that there are six tens and zero ones leftover. So the number 60, has a digit six, which is worth six tens and a digit zero, which has a value of zero ones. Hmm, What if I was to buy three extra strawberries, like this? How many strawberries would I've bought altogether? Now I'm going to give you a few seconds to think about it. Okay, let's count them all together. Well, I can count these bits in tens, so 10, 20, 30, 40, 50, 60, 61, 62, 63. So now I have 63 strawberries altogether. If I was to represent these 63 strawberries on a bead string, they would look like this. So I still have my six tens, but now I need to add three more beads to make them 63. So now I've got 10, 20, 30, 40, 50, 60, 61, 62, 63 beads all together that represent my 63 strawberries. So, in the number 63, there are six tens and three ones. The digit six is worth six tens, the digit three has a value of three ones. You can also represent my number 63 on a part whole model that looks like this. We know that altogether, we've got 63 strawberries. So 63 is my whole. Now, if I was to partition 63 into tens and ones, we know that 63 is made up of six tens like this, 10, 20, 30, 40, 50, 60 and three ones like this. Well, if I add my two parts 60 and three together, I will get the whole 63. I can write that as an equation like this, 63, which is my whole is equal to 60 add three. Remember I can also switch around my equation. So I can switch around my part and that will not change the value of my whole. So 63 is equal to three add 60. It doesn't matter which way round my 60 and my three go, if I add them together, they will still make the whole 63. So we've had to think about how a two-digit number can be represented on a bead string and in a part whole model. We're now going to think about how we can represent a two-digit number on a number line. And we can do this because as it says on my screen, a bead string is just like a number line. So here's my number line, it goes from zero to 100. And if I lie my bead string next to it, you can see that it goes up clearly in ones and in groups of 10. So it matches up perfectly to my number line. Okay, so we're going to represent our 63 strawberries that we had, at the beginning of the lesson on a number line. First, I'm going to show you what that would look like on my beads string along here. So remember we said that if there are 63 strawberries or six tens and three ones, I need six groups of 10 and three ones on my bead string. So this is what that would look like here. If I was to do that on a number line, I'm going to need to represent my six tens by doing six jumps of 10. So let's do that now. That's one jump of 10, two, three, four, five, six. So that takes us to 10, 20, 30, 40, 50, 60. Now I need to do three jumps of one because remember the digit three represents three ones. So 61, 62, 63. So I have my jumps of 60, my six tens add my three ones, gives me 63 and you'll see that on my number line, I land on 63 because I've done six jumps of 10 to get to 60 and three more. Let's have a look at a new example and try to put them in another two-digit number. I'm representing it on a number line. So I have a different number of strawberries here that are 10, 20, 30, 31, 32, 33 strawberries all together. So to represent that on a bead string that would look like this because I've got my three groups of 10 beads, 10, 20, 30 and my three ones 31, 32 33. How do I represent this on a number line? Hmm, Well, I can see straightaway that there are three tens, so I'm going to need to do three jumps of ten. One, two, three. So that's 10, 20, 30 and I've got three ones. So now I need to do three jumps of one, 31, 32, 33. Brilliant. So 30... So I've got my three jumps at 10, which is 30, add on three equals 33. Okay, team. So it's time for the talk task. And in today's task, you're going to need to follow these three steps on this left side of the screen. The first thing you're going to do is pick a card and partition the two-digit number that's on that card into tens and ones. Once you've partitioned it, I want you to represent that number on a bead string and count the groups of tens and ones. If you haven't got a bead string, you can use any other countable objects that you might find in your home. So pass this quite good one or Hama beads in Letgo. If you haven't got those things, you could always draw the tens and ones. Finally, once you've partitioned your number into tens and ones, you can use that information to draw the jumps on a number line and then write out the equation like we did in our new learning. I'm going to show you an example of one and then I'm going to ask you to do your task. So the number card that I've chosen is 27, it has two tens and seven ones. I will represent 27 on a bead string. I have two groups of 10 and then seven ones. I will represent this on a number line, I will make two jumps of 10 and then seven jumps of one, 20 add seven equals 27. So here, in my example, you can see I followed all of the steps and I've also followed the sentence structures to really help make my explanation clear. So when you come to do your talk task, I would like you to say the sentences using those structures because that's going to help with your learning. Okay, here are the ones that I would like you to have a go at and here are the sentence structures. So pause the video now to have a go at your talk task and press play when you're ready to resume your learning. Welcome back team. Let's go through these answers then. So I'm going to start with the two-digit number 16. So I have the number 16 and it has one 10 and six ones, to represent that on a number line, I should do one jump of 10 and six jumps of one. So that's what this would look like on a number line. The next one, oh, sorry, So that means 10 add six is equal to 16, you can see that in my jumps. The next one 71 has, seven tens and one, one. So I need to do seven jumps of 10, like this, that get me all the way to 70 and one jump of one. So 17 add one is equal to 71. And that's the equation that you should have had. Okay, 57 my number card, it's got five tens and seven ones, so I need to do five jumps of 10 and seven jumps of one. So 50 add seven, is equal to 57. Lastly, I've got the number three, which isn't a two-digit number. It's just a single digit number. And as I haven't got any tens, I'm not going to make any jumps of 10. I'm just going to make three jumps of one, which would look like this. And I've got the number three. Good job, if you've got all of those right, well done team. And now I'm going to use what you have learned about place value to find a mystery number in our develop learning. So I have a clue here and that is going to help me identify the mystery number. It says, the value of the digit four in my number is four tens and the number is less than 45. The digit in the ones place is one more than two. Hmm, let's try and represent this number on a bead string with the information that I have. So it says here that the four digit is worth four tens, so I need to have four groups of 10 beads on my bead string, which is equal to 40. It says that the ones digit, or the digit in the ones place is one more than two. I know that three, the number three is one more than two. So I'm going to need three ones. So my beading would look like this. I have my four groups of 10, 10, 20, 30, 40 and my three ones. 43 is less than 45, so I think the mystery number is 43. Let's see what this would look like on a number line. So I have four tens, which means I'll need to make four jumps of 10, 10, 20, 30, 40, that's my four jumps of 10. And I've got three ones. So I need to do three jumps with one, 41, 42, 43. Then my mystery number is 43. Let's try the next one. The clue says there was a nine in my number, it is in the ones place. The tens digit is two more than six. So to figure this out, I need to think about what information I already know, what information do I know about the tens digit? And what information do I know about the ones digit? Well, it says here that the digit nine represents nine ones because it's in the ones place. So I'm going to need nine ones in my number. I can also see that the tens digit is worth two more than six, which is what it says here. So two more than six is eight. So there must be eight tens in my number. So my number line, I'm going to need eight jumps of ten, one, two, three, four five six, seven, eight, that's 10, 20, 30, 40, 50, 60, 70, 80 and nine jumps of one because remember the nine is in the ones place, which means I have nine ones. So 81, 82, 83, 84, 85, 86, 87, 88, 89. So my mystery number is 89. I can represent that on a bead string to remember. So I need my eight tens and nine ones, which makes 89. let's count them 10, 20, 30, 40, 50, 60, 70, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89. So that is how I would represent my two-digit number 89 on a bead string and on a number line. Right team. It's now your turn to have a go an independent task and you are going to try and find some mystery numbers just like we've done in our developed learning. So there are four clues for her, for you to solve. And I would like you to use a bead string or other countable objects in your home and a number line to find out the mystery number. Good luck. Pause the video now to complete your task and resume once you're finished. Welcome back team, fantastic effort. What hard work I'm seeing today from you? Brilliant. Let's have a look through those answers and see if you managed to solve the mystery number clues. So my first one says, the digit three in my number stands for three tens. So straightaway, I know I'm going to need three tens. The digit in the ones place is one less than six. So one lesson six is the number five, so that means I'm going to have three tens and five ones. So I have the number 35, that's my mystery number. And it would look like this on a number line with three jumps of 10 and five jump of ... My apologies, that's actually incorrect. You should have five jumps of one. And all my beads string, I've got my three tens and five ones beads. The next one is going to be 43 because we know that the number four represents four tens and then number in the ones place is one more than two. And one more than two is the number three. So on a number line, I've got my four jumps of 10 and my three jumps of one. The next one is the number 13. And I know this because the digit three is three ones and the number is less than 15. It's got to have just one 10 because it's got to be less than the number 15, which has just one ten. So I would represent it like this, with one jump of ten and three ones. My final clue says that, or the, my final clue, the mystery number is going to be 89. And we know that because the nine represents nine ones. So I've got my nine in the one's place. We know that it's got to be greater than 60 and the digit in the tens place is one more than seven. One more than seven is eight, so we know that we're going to need eight tens. So here's my 89, represented on a number line and bead stream, I've got my eight jumps of 10 on my nine jumps of one. Well, that concludes our lesson for today team. And I hope you really enjoyed it. I definitely enjoy doing all of the mystery number solving, I thought that was a really fun task. I hope you're leaving this lesson feeling a little bit more confident about representing two-digit numbers on a number line. I'll see you very soon for another session. Bye, bye. All that's left for you to do now guys is complete the quiz. So once the video has ended, you know what to do and I'm really excited to see everything that you can remember from today's session.

If you'd like to, please ask your parents or carer to share your work on Twitter tagging @OakNational and hashtag learnwithOak.

Representing 2-digit numbers (Part 1)

Representing 2-digit numbers (Part 1)

Slide deck

Lesson details

Key learning points

Licence

Video

Worksheet

Starter quiz

5 Questions

Exit quiz

5 Questions

Lesson appears in

UnitMaths / Numbers within 100

Maths