Lesson video

Hello, hello, hello, it's me, Mr. C.

Welcome to today's lesson.

Hope you're well, hope you're rested.

Hope your brain is engaged, hope it's more alert than mine.

Mine is certainly not playing games with me today.

So hopefully you will be able to help me through this lesson.

All right, let's take a little look, shall we? Make sure that you've done our Knowledge Quiz and then come on back as soon as you're ready.

Welcome back ladies and jelly spoons.

Shall we take a little look at what's happening today? Well, before we do, let's just get our fact.

So did you know that China has the world's largest population? That's 1.

42 billion people living in China.

And if you look down there, that's a little outline of what China would look like on a map, obviously it's not red with these stars on, it's got the flag on the background.

Now that's followed by India with 1.

35 billion people.

Now the next 5, most populous or fullest countries, if you like, countries with the biggest population, are the United States, Indonesia, Brazil, Pakistan, and Nigeria.

And when you add together all the people in the United States, in Indonesia, Brazil, Pakistan, and Nigeria, that's still less people than there are living in India alone.

That is immense, it just really hurts my brain, trying to get my head around, that, to think that five other countries, add them together and five big countries, by the way, have still got less people living in them than India and also China, crazy.

Well, take a deep breath.

Let your mind settle after that, and let's move on, shall we? So for today's lesson, you're going to need this equipment, your pencil, your ruler, something to work on and some quiet, no distractions.

So probably not in the middle of a busy city in India, not very quiet and peaceful without distractions, so much to see there.

So maybe just your room and with nothing around you to disturb you, all right.

So let's take a little look at how things are going to go today.

So our agenda for today, then.

We've done our Knowledge Quiz.

We're going to look at our key learning and vocab in a minute, like we always do, and then you're going to do your number trees warm up, which I think you're getting really good at.

Might find a new one for next time round.

Let's recap then on symmetry, talking about what it means.

Then we've got our main activity, which is all based on symmetrical patterns today.

Not in 2D shapes, but in patterns to start with, and then a final Knowledge Quiz to see what you remembered.

All right, so today we're going to look at recognising lines of symmetry in a 2D shape and in a pattern.

And our key vocab is 2D, regular, irregular, symmetry, symmetrical, mirror line.

Remember the mirror line was that dotted line we were drawing that shows what we can fold the shape.

That is also the same as our line of symmetry.

So here are our number trees, you know how these work, you are experts at these now.

Just to recap, in case you have forgotten.

When you add together these two numbers, they produce the number above, and you're going to do that until you fill up the entire tree.

Now, if I have the number at the top and I'm working backwards, I could look here 20, and 11 here, 11 plus something makes 20.

So instead of doing 11 plus something makes 20, I could do 20 take away 11 makes, hmm, because I'm using the inverse.

So give that a good go.

For example, here, look, 5 plus something makes 11.

What do I add to 5 to make 11? If I'm not sure, I can do 11 take away 5.

So 11, 10, 9, 8, 7, 6.

So in there I'm going to write in the number 6.

Can you do the rest? Off you go.

And we're back in three, two, one, and we're back, hello, hello, hello, all right.

Let's take a look at those answers, shall we? Taking a look there.

Now for this one, I tried to make the third one along a little trickier this time, 'cause I gave you far fewer numbers than before, but hopefully you managed to work that out.

I wonder if it would be possible to work out the final number if we just had this one and this one, hmm, I wonder if that would be possible.

That's something I'm going to give a go, later, I think, when I have some time to myself.

All right, your brains, I'm hoping now, are fully functioning and raring to go.

So let's do just that.

So let's just really quickly recap then on what symmetry is.

If you remember, I said to you yesterday, symmetry's all around us, we see it in nature.

And I bet since we talked in this last session about symmetry, I bet you've spotted things that are symmetrical.

I bet you've seen things out and about in your house.

Wallpaper's a great place to look for lines of symmetry, so you may have seen that.

If you use place mats on a table, quite often they're symmetrical.

Lots of things that are patterned, your duvet cover, plenty of patterns.

So something is symmetrical when it's the same on both sides.

Now a shape has symmetry if you can draw a central dividing line, the mirror line where you can follow it, just like we can see in this butterfly and also tiger picture.

And we see plenty of symmetry all around us, as I say.

Now this is quite a basic, sort of year one, kind of explanation as to what symmetry is.

As we found out yesterday, things can have many lines of symmetry, not just one straight down the middle.

So a line of symmetry is a place where a shape can be, I guess, folded if you'd like, and both sides of the line will match up equally, probably exactly on top of each other.

So look at these six shapes here.

Some of those shapes have a line of symmetry.

They may have more, some of them though, have none at all.

Spend a few seconds now thinking to yourself, which ones have lines of symmetry and which don't.

Now, this is a really good opportunity for you to use sort of visualising skills where you think to yourself, okay, if I could lift this off of the page that I'm looking at now, how would it work if I folded it in real life? So you're going to use your imagination a little bit here.

Some of the shapes are really obvious and you can spot it straight off.

So think about it.

Which of these have lines of symmetry? I'm going to give you, ooh, five seconds to have a think.

Two, one, and let's get ready for the big reveal.

Drum roll, please.

Dreadful drum roll, sorry, ta-da! Those shapes all had lines of symmetry.

Let me just really quickly show you on this sheet.

Straight down there, right through the middle here, from this point through to this point and straight down the middle of the face, right between the eyes there.

These had no lines of symmetry.

None here, nope and sorry, no.

Just, ding, ding, ding, these three.

So, well done if you spotted them.

If you remember, however, yesterday, the only reason we can say at the moment, this one has a line of symmetry, is because with it being a face, it's an emoji kind of face, okay? Real faces are not symmetrical straight down the middle.

I did mention that yesterday, I wonder if any of you went and took a little look at some pictures online where they'd put symmetrical faces together.

It looks very strange.

So have a look now then, we've looked at them in terms of shapes, like this, but can we also make symmetrical patterns? Now on each of these, the pink dotted line, that's your line of symmetry, that's your mirror line.

Can you match the pattern from one side to the other by shading in the correct squares? Now, when I show you the answers, I know what some of you eagle eyes are going to say, and this goes out to my special friend Eagle Eye, he knows who he is.

If you spot this, and my answer's well, do you know what? I'm not going to tell you yet.

When we get to my answer reveal, I wonder if you can spot why mine aren't necessarily symmetrical.

It'll make sense when you see the answers.

So can you complete these patterns, by shading in the correct squares? Have a go and then and Eagle Eyes, this is going straight out to you, okay, look for where I may not be quite showing a symmetrical pattern.

Come back when you're ready.

And back in three, two, one.

Here I am, let's see, shall we? Now, this is what I'm going to say then, my patterns are mostly symmetrical, but there's something about them that isn't symmetrical.

Eagle Eye, did you spot it? I've put the squares in the correct place, but I've used a different colour.

So the fact that I've used a different colour means that it's not strictly symmetrical, but the colour is just so you can see where I've added them in, okay, so if I wanted to make it perfectly symmetrical, these would be grey just like on this side.

But here you can see we've got kind of like stripes almost.

Here, here, hopefully you managed to get that, now if I were to cut this strip for example, and then fold it along that line, this square would end up touching this one and so on and so forth.

So we'd know that it was a symmetrical pattern.

Great stuff, all right, let's keep those juices flowing, then, and take a look here.

So now that we've looked at the patterns, can you look at some slightly more complex shapes? Now these are obviously irregular shapes.

What you need to do now is complete the other side, crossing that line of symmetry.

Think very carefully, looking very carefully.

And actually, now you're not going to fully believe me, but counting really helps, okay.

Let me explain why.

Counting can really help you because I can say to myself, okay, let's look at this shape here, okay.

I have my black square and then one, two white squares until the mirror line, so one, two white squares.

I'm going to work from the mirror line out.

One, two white, and then a black, so one, two white, and then the shaded-in part.

And look, here I can see one, two, three shaded in, so one, two, three shaded in.

Do you see what I mean by counting them along? If you can count them out like that, it's really quite a useful way of doing it.

Okay, so think about that.

Start from your mirror line and work away, counting as you go, and that should help, let me just show you one more time what I did there.

So here, I saw that here's my mirror line.

I had to go one white square, two white squares, and then I hit the shaded square.

So it's the same the opposite way.

One white square, two white squares, and then I hit the shaded square.

Ooh, little bit of a rhythm, there.

And here it was one shaded, two shaded, three shaded squares, one shaded, two shaded, three shaded squares.

Okay, I think I've created a monster now, 'cause you're all going to be going one shaded, one blank, one blank, I'm finished, one, you're going to have these dreadful rhythms happening in your head now, I'm sorry, not sorry, because if you get the answers right, I'm super happy.

So use that counting technique if you need to.

Pause and come back when you're ready.

Hello, welcome back.

Here we are, let's take a look, shall we? Here are my reveals, then, again, you'll notice that I've done them in a different colour, so not strictly symmetrical, but that is so they stand out so that you can see my working clearly, okay.

So just cast your eyes over those.

Not too difficult, how many of you have now got a really annoying rhythm of blank square, blank square, one shaded in, one shaded, blank square, one shaded in, and so, how many of you have got that going on? Mmm, I have, but I found that it really helped.

So we started on linear patterns.

Then we've moved to these grid patterns.

Let's really mix it up, shall we? Because you're ready for this, dun-da-da-dun dun dun dun da.

Look at these, this time we have colours.

And if you don't have colours at home, don't worry too much.

You can just shade in the square lightly with pencil and write R for red, B for blue, G for green and Y for yellow, that's fine.

So don't worry if you don't have colours, this is still doable, okay.

So you're going to be spending some time now looking at how you can transfer those patterns across that mirror line.

Now I will say, be really careful, because while I was putting the answers together, I ended up doing it about, well, I'm going to say probably four times until I got it right, because I rushed.

So don't be me, don't be that rusher, take your time and really get great results, okay.

So you're going to be filling in the correct squares to make both sides symmetrical.

Count if you need to.

So remember it was red square, white square, blue square, red square, white square, blue square.

Do it one row at a time or one column at a time, and that will be a good way to do it.

So there are two sets of these, one, two.

Have a go and then let's do the big answer reveal.

Happy end, good luck, you guys.

Slow and steady wins the race.

And we are coming back in five, four, three, two, one.

Hello, we're back.

Shall we see the big reveal of the answers? Hopefully it wasn't too tricky, just takes that little bit of slowing it down, doesn't it.

So here we are here, here our first set.

And if you just look very carefully, you'll see that they've built up a bit of pattern, I've tried to match the colours as best as possible, They're not spot on, but I've tried to match them.

I wonder if you have a favourite out of them all, as well.

On this page, mine would be this one.

Not because it was the simplest, but just because I think it looks way nice and clear.

On my next set, I really liked this one.

Now take a look here, right or wrong.

I was hoping some of you are going to say wrong because when I first looked at it, I forgot that my mirror line wasn't running across the middle and that it was going from top to bottom, so I made a big old mistake the first time I did that.

I couldn't figure out how to do that because if my mirror line had been running along here, I'd have had to put my yellow on top of the blue.

And I kept getting really puzzled by that because I hadn't looked carefully at the question.

So see, mirror line has changed direction.

If you spotted that, then you are a better person than I, because you were much more of in the detective-eye zone, so well done.

So we've explored now then, how you can look at symmetry not just in shapes, but also in patterns.

So go back, take a look at our final Knowledge Quiz for the day and then work your way through that and come back when you're ready, so that we can say a big old farewell until next time.

And we are, back, hi-hi-hi.

So hope you did a great job on your little Knowledge Quiz at the end there, well done.

Big, big congratulations for today's lesson.

That last activity was a real stinker, I thought, and it caught me out far too many times.

So well done to those of you for getting through it, and those of you who didn't get it right first time, well done for persevering.

That is a very admirable quality.

So until next time, that is me over and out.

So that's it for me, Mr. C.

See you soon, bye-bye.