Which letter DOES have a line of symmetry?

Which letter DOES NOT have a line of symmetry?

Which shape does NOT have a line of symmetry?

How many lines of symmetry does an equilateral triangle have?

How many lines of symmetry does the number 8 have?

To complete a simple symmetrical figure

﻿Hi guys, it's me, Mr. C, hope you're all well and ready to continue with our shape and symmetry topic in maths. Where this next session we going to be looking at investigating using symmetry. So if you haven't already, you know the score, take our knowledge quiz, and come back when you're ready to move on, so that we can get on with today's learning and go through our agenda, our key vocab and move on with something new. Welcome back, how was that first knowledge quiz for you? Did you manage? Did you whizz through is your brain amazing? I'm sure it is. So let's take a look at something else, amazing. This amazing fact. So here you've got a picture of the most beautiful car. It's a stunning car called 'La volture noire', which is French for the black car. Although we have mentioned native name. But what if they did one in blue? They'd have to change the name, right. I wonder if you can figure out what that would be called in French? Well, as of 2020, this is the world's most expensive car. So if you want to buy one, so it's going to cost you around 19 million dollars. That's easy, right? It's about 15 million pounds. Yeah. I'll take two of those, please. 'Cause clearly, anyone could afford even one of 15 million pounds, 15 million pounds for a car. I'll take a taxi, thanks. That's crazy, right? I mean, it looks great. I'm sure it feels great to drive but can you really justify that much money on a car? Well, that's a little bit excessive. So before my head explodes from the fact that it costs that much, shall we move on, lets. So today, as usual, you're going to need the same equipment as we normally would, your pencil, your ruler, something to work on. Somewhere with no distractions, if you're sitting by a racetrack with these amazing cars going past, maybe go somewhere quieter, so that you're not going to get disturbed. So our agenda today we've done the first bit, we've done our knowledge quiz, well done. We're going to move on to our key learning vocab in a moment. And then we're going to try a new type of warmup called secret value. And I'll explain that when we get that, then we going to recap on symmetry and use some main symmetry activities just to show the skills we've been developing over the last few sessions. And then finally, your last knowledge quiz to see what it is that you've remembered from the session. All right, so here we are with our key learning. So today we're going to investigate a problem using symmetry. And so that must mean that a lot of the words are going to be repeated in our key vocabulary. symmetry, symmetrical mirror line, shape, grid, 2-D and investigate. Well done, remember 2-D, 2-D.imensional, width and height are the two measurements that we can make there. Mirror line don't forget is the line with which we reflect across. Or if you wanted to do it on paper we will be folding and symmetry and symmetrical just means that they're identical. Let's recap on that in a little while. So this is what I meant by secret value. And I'm going to explain how it works. You've got four symbols there in this grid, you have the heart. now, the plus sign, the star, like all of you and the triangle. Each of those has a different value. We need to try and figure out what each value is. So I'm going to look here, first of all, I have four stars. But, wOw, what's wrong with my eyes? They're not stars. They're our hearts. So sorry, four hearts. I've got new glasses you think I'd be able to see that? Now four hearts when I add them together make 24. So something add something, add something, add something is 24, and they all have to be the same. So it's the heart listen to my clue here. The heart four times, makes 24. Four times heart, makes 24. Four times Hmm, is 24. Four somethings, is 24. Once you've got that, everything else becomes a lot easier. If didn't catch the hint. What do I multiply by four to make this? So, this is going to take some of your skills from yesterday, from the last session, your mental math skills of multiplication, knowing your times tables is going to really help you with this activity. Also, knowing how to use the inverse will help as well. So, can you figure out what each of those symbols is worth? Give it a go. It's the first time we've done it. If you don't manage it, don't worry. We'll be talking through it in a moment. If you do manage it, amazing. So give it a go. And welcome back. So how did you find that? Not too tricky, right? Let's just go through them a couple of them, and then I'll reveal the answers to you. So I gave you a big fat clue for that first one. I said we have four of the same thing, which added together to make 24. If I add something four times, I might as well just multiply it. So I need to know what do I multiply by four to make 24? So four times something makes 24. What do I multiply four by to make 24. Just counting on in fours really, until you get 24. And you should have had six, four times six is 24. Now, now that I know that this is what I'm going to do next, everywhere I see a heart, I'm going to write the number six. So six add six, add this add this makes 30. Six at the star at two triangles is 24 and so on, Okay. So what I would do here is I say six add six is what 12. Then I would do 30, subtract 12 to see what I had left. So 30 take away 10 would be 20. Take away the other two from the 12 would be 18. So I'm now on 18. So something add something or something times two is 18. So two times something is 18. Now if you didn't manage it the first time I've given you another couple of hints there. So, pause again and give it another go. If you've already done it, check see if what I've started on here now, especially in this row six add to something add to six add to something, See if that, links in with what you were doing. So have another quick look at it. Okay, so we're back. Let's double check then I've done, this one here I've worked out that in my heart is worth six six add six gives me 12. This whole row had to make 30. 30 takeaway to 12 I already had gives me 18. Two times something makes 18 which is what these green crosses would be worth. What do I multiply two by to make 18? Yes. Okay, now if you remember with the heart Once I've got the value I want to put it in. So I'm going to do the same again. This should now help me with this one, nine add nine is 18. And I've got to add the same number again twice to make 26. So I'm going to do 26 take away the 18 I already have. So I'm going to count on 18 to 26. 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 26. So I've got eight left. So something times two and two. Gives me eight. What do I multiply by two to make eight? Yep, so each of these is worth four. Am going to go and put that in. So six add four gives me? Yeah, 10. And then I've got two of the same to make 24. So 24 take away the 10 I've already made would give me 14. Two times something makes 14, what do I multiply two by two, make 14? Seven. And then all I would do so just go through and double check that I got them all right. Now that may have seemed tricky, but actually, I think that when you've done your number threes, they've actually been harder. So if you've managed that, on our number threes, you can easily manage what you've just been doing there. So just read quickly then, here are the answers again for you. We definitely going to do another one of these, I really enjoyed them. So take a look. Here's your answer, Well done. So just to remind you that what I did was I went through and I found writing in those numbers really helped. Excellent stuff, well done, folks. Let's recap then on our learnings for today. So symmetry Don't forget is that mirror line through a shape. That means that both halves on either side of that mirror line are identical. They're exactly the same, just in reverse. I'll get our very basic explanation of what symmetry is. So let's take a look at this. Now here I've got a block picture. at the moment, it's just some blocks. Your task is going to be to start off with here, Can you make this symmetrical? Do you remember how counting helped Let's take a look, shall we? Let's start on this top row here. This black line here is our mirror line. Sometimes it will be a solid black line, sometimes it will be dotted, I'm going to use counting and number our works outwards from that mirror line. So I've got one white, two white, three white, grey, grey, one white, two white, three white, grey, grey. So I couldn't do it in lets see how it stands out. One white, two white, three white. Shade it, shade it. One, two, three, shade, shade. One, two, three, shade, shade. See, here I've got one, two, three, four, five, shade. One, two, three four, five, shade. and then one, two, three, shade. So one, two, shade. One, two, shade and then straightaway mirror line shade, mirror line shade, do you see what I'm doing there? let see how I'm using accounting to help me. I could also say well once I've got these two I know that diagonal and diagonal are both shaded. Here's my two, diagonal and diagonal. Whatever method works well for you, give it a go see if you can complete that shape, that picture and come back when you're ready. very best to look guys. Of you go and we are back. How did you manage ladies and gents, shall we find out? So you should have ended up with something that looks like this and don't forget. Yes, it's not particularly symmetrical. If I've done one half in grey and one half in orange. I've just done that so it stands out for you. Okay, here's a little test for you then if I were then to shade in this one, how would I make it symmetrical on the other side? In a count look, one, shade, two, shade, three, shade. One, shade, two, shade, three, shade, well done. Well what about if I did, shade, white white, shade, shade, shade, shade, White, white, shade, shade, shade. There you go. Good job, all right. Take a look here than, this is slightly tricky because this time we're not shading anything in you're going to be completing symmetrical shapes using lines. So for example, let's look at this one. From the mirror line. I got one line out. So one line out. From here, the mirror line I got one line out. So when I look how counting helping again, so I've got one line out, and then I have to have my line dropping down one line out, line dropping down, one line out line going up, one line out, line going up, I can then pretty much tell that this is going to go. Yours going to be much neater So give that a go and see if you can fill those in. Remember, you might feel crazy doing all the counting and talking out loud, but it does actually help. Alright, so what you're doing now then is completing those shapes. Cross the mirror line and after all the mirror line is not always going to be going the same way. And then come back when you're ready. Hi, so you managed, so we take a look. Hopefully you will have ended up with some shapes that look a bit like this. The counting method really does help. The only time for a tricky is if the lines are diagonal. But what I did here, here's my top tip here I went, I saw the bit that was already on, which was this bottom part here, I could see that from the mirror line, I went one square, two squares out to the point so one square, two square out to the point and then just joined them up. Easy really wasn't it. Other ways that you could do this to make it easier is if I'd already had this half, if I shaded it in, that would have also made it easier to spot where those lines would have to go on the other side, 'cause I could count the squares for shading as well. It's just a couple of methods that you could use. So you could either count the lines or the corners or shade them in and count the squares. Either way, works. So here's the second part. It's the same thing again. So maybe use that idea now, let's look at this one together, for example, to get my triangle, right, if I look at how many corners I've gone through, I've gone one, two corners. So let's do the same, one two corners there's my next point all that I need to do is join everything up. Have a go. Come back when you're ready. Best of luck and we're coming back in five seconds. Four, three, two, one. welcome come back, shall we see, let's. So once I've got that little line, that dot here, all I had to do is join up my lines. Everything else fell into place. That would be my tip for with diagonal lines in symmetry. Well done, by the way, we're actually moving on to here five symmetry doing this stuff here. we just finish looking at little blocks for symmetry, but because with our diagonal lines and full shapes, nice work, folks. All right, we're almost done. So Off you go and do your knowledge quiz for today. Final one, when you're done with that, come on back. All right, here we go. We're back, well done, folks. Great session today. Really proud of you and all of your efforts as usual. So that's remains for me to say is, well done for your hard work, and until next time, that's it from me, Mr. C. See you Soon, bye bye.

A line of symmetry can also be called....

A regular pentagon has how many lines of symmetry?

How many lines of symmetry does this isosceles trapezium have?

Which of these numbers has 2 lines of symmetry?

Quadrilaterals have 4 lines of symmetry.

To investigate a problem using symmetry

In this lesson, we will recap the knowledge we have developed on symmetry. We will investigate different types of shapes and patterns and use our new knowledge to solve problems based on their lines of symmetry. We will draw, investigate and justify our ideas.

Maths

Y4 Maths

Key Stage 2

Year 4

To investigate a problem using symmetry (Part 1)

2-D Shape and Symmetry

Geometry

THEME

UNIT

Shape and symmetry: To compare and order angles

Shape and symmetry: To identify right angles

Shape and symmetry: To identify acute and obtuse angles

Shape and symmetry: To investigate angles within shapes

Shape and symmetry:Identify angles within shapes

To compare and classify 2D shapes

To compare and classify quadrilaterals

To identify and classify right angled and equilateral triangles

To Compare and Classify Isosceles and Scalene Triangles

Quadrilateral Problems

To identify lines of symmetry in 2-D shapes

To identify lines of symmetry in a pattern

To investigate a problem using symmetry (Part 2)

How many right angles does this shape contain?

Estimate this angle. Which guess is closest?

What do each of the angles in a rectangle measure?

What kind of angle is less than or equal to 45 degrees?

What kind of angle is more than 90° and less than 180°

How many degrees on a straight line?

Which angle is the odd one out?

Angles in a triangle add up to how many degrees?

If I imagine the minute hand of a clock pointing at 12 is a measurement of 0°, what number would the minute hand be pointing at for 180°?

How many lines of symmetry?

Lesson overview:To investigate a problem using symmetry (Part 1)

Core Content

2-D Shape and Symmetry: