 PakehaDon, ka interconnectu usiarion ka magikulia... Maithai iade tu saguru, sa maithanama lamia? PakehaDon ka magikulia, ka pagdumaneraibe lui ki uu ti fa2 Pura moa gadaf na puna whim 230 da? therapeutic card Видtoun moa gadaf tu bontsta ansu ki Ball fib gadaf na puna sch �u tuni or a bit can be turned on. Where else have we learnt about bits before? Turn to the person next to you and tell them about that. And eyes this way. So bits, did anyone mention in their whispering did anyone mention the word binary numbers when we learnt about binary numbers the other day? Yeah, so these are bits and these could be like the binary numbers, right? They could be on or they could be off. Cool, has she got five by five? Yeah, cool. Thanks, Allie. So I'm going to make this magic trick just a little bit harder for myself and I'm going to put an extra column down here and I'm going to put an extra row under here just to make it hard. Right, I've done that now. I've got a really bad memory and I can't see very well when I take off my glasses. Oh, I can't see it all now. Right, so I'm going to ask someone to go up and turn one of them over. Hands up, who thinks I'd be able to guess where it is? Hands up, who think that it's impossible if you've got a bad memory? Or it's even impossible if you've got a good memory. Hands up. OK, let's see. Riley, can you go up and turn one over? Everyone else, you need to check either that he is turning it over or you need to check that I'm not cheating and I'm not looking. I'll take my glasses off to be even sure. Everyone say done when he's done it. Done! Right. Hmm. Riley, Riley, Riley. Right or wrong. Was it a fluke? It could have been a fluke, right? Thanks, Riley. Let's give them a big hand. Thanks, Riley. OK, who thinks they can trick me maybe because it was on the bottom row? I'd memorise the bottom row. Maybe, maybe, maybe. Sammy, I'm going to go over here this time so I'm definitely not cheating. You guys need to watch if Sammy's turned one over and some of you need to check that I'm not cheating and I'll even turn off the eyes of the back of my head just to be sure that's not happening. Right, let's have a look. Sammy, Sammy, Sammy. Right. Right or wrong. Was I right? Awesome. So if I get it right two times, is it a magic trick or is something else going on? Hands up if you think it's still a magic trick. Hands up if you think there must be something going on. So let's look at what is going on. We had these just as we had them before and we go through the rows. How many black cards can you see in this row? How many black cards in this one? Now let's look at these columns. How many is in this column? These numbers all have in common. What are they? How would we classify those numbers? Hands up if you agree with that statement. Even numbers and you are right. You are right because I said I was going to make it harder by adding the extra column in row, right? Did I make it harder or easier? Easier. Why did I make it easier when I added a black card here onto this row? What was I doing? Yeah, well if I didn't do that how many black cards are there now? When I add a black card there what am I making it? Taking it from odd to even, right? So actually by adding that column and adding that row I made all of the black cards even. So I was able to correct the mistake, correct the error which is the one that got flipped over. Okay. So let's see how that worked. I'm going to actually take away the extra column and the extra row and you're going to tell me what to put. I am also going to rub out the numbers so you've got no prompts. Okay. Are you ready? I want you to call out black or white and tell me what I have to do here. What do I have to do here? All those rows are done, let's do the columns. Okay. I want you to see what's happening here because if I put it white there does that make that column correct? Yes. Does it make that row correct? Okay. So that corner there she is putting two of the rows and the columns into place so it's quite an important card, isn't it? Okay. So now that you've seen how it works who thinks they would like to have a go at doing this? Who thinks they'd like to have a go? Robert, do you think you can do it? Okay. So you're going to stand over there, close your eyes turn off the eyes at the back of your head power them down and I need someone who's going to come up and change it. Come up and change it for us. Change one. You guys look and check that he's just changing one. I'm going to look and check that Robert's not going to turn around. Cool. What are we going to tell Robert? Okay, Robert come over here and we're just going to help you with this. So this row here, how many are there? Four. Is that okay? Yes. What about this one? Four. Is that okay? Yes. What about this one? Four. Is that okay? Yes. What about this one? Three. So there must be a problem. Let's put a circle around there because I think you're right. I think there is a problem because it's an odd number. Do we have to check the next row? No. Why not? We've already found the answer and we know there's only one error to detect, right? So now let's look at the columns. How many is in here? Two. Is that right? Yes. What about this one? Six. Is that okay? Yes. What about this one? One. So there must be a detective problem. There is a problem in there. Let's have a look at that. So, which card was flipped, Robert? This one. Would you like to turn it over? Good work. Okay, hands up if you agree with Robert that that was the one that was changed. Cool, let's give him a hand. Well done. Thanks, Robert. How are we learning this with a whole lot of magnets on the board and how does this relate back to the computers? Because what we've actually got here is a representation. This here that Ellie put up, this is the data for a piece of music she's written and she's now uploading that up to the internet. Now, if she's doing that, she's probably using phone wires and things and so what we're doing is just adding a little bit more data to her file here and her data and what that's doing is if there's any interference, if for some reason a signal is off rather than on, it means that all of this together can be corrected in the computer and it stays the same for the person who's receiving it at the other end. And that's the same with your CDs and DVDs. So hands up if you've ever had a DVD where it's starting to glitch, it's starting to get pixelated or the sound's not working. Right, so hands down, if you turn your DVD over you'll see lots and lots of shiny and dull things on it. Each one of those is a bit and it holds billions of bits on your DVD and what happens is if you get a scratch on it or if you get one flick of dust, if you didn't have this extra data your DVD would be of no use. You'd have to throw it away. But the DVD has this extra data on it and so if one flick of dust gets on it can cope with that, it'll just correct it. And it has to be quite a decent scratch before it starts to pixelate. Have you seen the scratches like have you taken the DVD out, looked at it and go whoa, that's really dirty and scratched that must be why it's not working. Have you ever done that? Cool. And you clean it and it works again, right? Hopefully. And that's because you've got it to a state again that it can now read and it can correct all the errors in the detections. Cool, thanks.