Further practice buying items with different value coins

Key Stage 1

Maths

Multiplication and money

﻿Hi everybody. Welcome back. We're going to start this session by looking at the practise activity that I set for you last time. We were looking at how many coins you might need from each purse to pay for your 30 pence boat. Okay? So, how many pennies did we need from our one penny purse to buy our boat which costs 30 p? I've got all my pennies out and laid out ready to count and they're going to change colour as we count them. Are you ready? One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. And I'm going to stop there because I've got enough now. I didn't need all of the pennies that I had laid out. Do you notice anything about the arrangement of the pennies which is going to help us to know how many we needed? Good. I wondered if you'd spot that. You might be able to see that the pennies are in tens frames, the shape of tens frames. So we can see that there are three of those. So we know we've got 10 and 10 and 10. So we needed 30 pennies to buy up 30 p boat. So the number of pennies we needed was the same as the cost of the boat. And that's because, good, the pennies are all worth one. Now I've put all my one pennies away and I've tipped out my purse that has the two pence in. I've made a bit of a mess. They're not very ordered this time, they're all over the place. So we're going to need another way of counting them. Okay? So I'm going to get out my pen and as we count them, we're going to mark them off. Okay? So let's count. What are we counting in? We're counting in twos because each coin has a value of two. Okay. Let's stop when get to 30. Ready? Two, four, six, eight, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30. There we go. That's where we need to stop. So we've marked off all the ones that we counted. Okay? So now we need to check how many coins it took us to get up to 30. Are you ready? One two pence piece, two two pence piece, three two pence piece, four two pence piece, five two pence piece, six two pence piece, seven two pence piece, eight two pence piece, nine two pence piece, 10 two pence piece, 11 two Pence piece, 12 two pence piece, 13 two pence piece, 14 two pence piece, 15 two pence piece. So, I have, the boat cost 30 p. Each coin has a value of two p so I need 15 coins. So now we're going to buy our boat again. But this time we're going to use our five pence coin purse. And instead of marking them off, we are going to move them. So the coins that we use will be in a different place when we're finished so we can see how many we used. Okay, you're ready to count in multiples of five? Five, 10, 15, 20, 25, 30. So we can stop there, well done. Have a look at the coins that we've moved. Can you see how many there are? There are six. Well done. Okay and we can see them in a bit of a pattern. We can see that there are three there and three there. So we know we have six. Now we're going to use a different purse. Inside my purse are 10 pence piece coins. Okay you can't see them, but they are in there. I promise. And we're just going to count them straight out. We're going to get them out and we're going to count them. Are you ready? We're going to count in multiples of 10, right. 10, 20, 30 and we stop there. So we've just got three, 10 p coins. The boat cost 30 p, the value of each coin is 10 p. So I need three coins. Because you did so brilliantly with all those activities, we're going to move on now. So I've got a new question for you. We're going to think about how many coins do you need to make a hundred pence in 10 pence coins. Okay? And we haven't got any equipment this time. Okay? So what we're going to do, is we're going to put our imaginary 10 pence pieces. We know what they look like. We're going to put our imaginary ones in our head. Okay? So I want you to be able to picture them there. And we're going to count the coins in our head. We're going to use our fingers to help us keep track this time. Okay? So we skip counting 10 pence coins. Are you ready? We're going to use our fingers as well. I can see them in my head and I'm going to count 10, 20, 30, 40, 50, 60, 70, 80 90, 100. So I stop at 100. And can you tell from my hands? Can you tell from my hands, how many 10 pence piece coins I needed to get me to 100? That's right. 10. We needed 10 coins. We skip counted 10 times. So I just want to double check that we were right. I'm pretty sure that 10, 10 pence coins make 100 pence. But we're going to use our whiteboards and do some jottings to help us. Okay. So I'm going to draw some circles which will represent our coins. And our coins value were 10 pence. Okay. You ready? So we're going to skip count in tens. 10, 20, 30, 40, 50, 60, 70, 80, 90, 100. Brilliant. So we were correct, weren't we? We can see that because on our board we have a row of five coins and a row of another five coins. So all together we know we had 10, 10 pence pieces which make a hundred pence. Right. Here's our next question. I'm going to read it to you and then I want you to think about what is the same as last time and what is different to last time. Okay? So how many coins do you need to make 40 pence in 10 pence coins? How many coins do you need to make 40 pence in 10 pence coins? So what's the same? That's right. We're using the same value coins this time. But what's different? We're making a different amount. So this time we've got to get to 40 pence still using 10 pence coins. I think that some of you might be able to have a guess or predict how many of those 10 pence coins we're going to need. Have you got an idea? Let's check by skip counting. I'm going to use my fingers again to skip count. Are you ready? 10, 20, 30, 40. How many 10 pence coins? We need four, well done. We didn't even really need to imagine our coins in our head that time. Did we? We knew that if we skip counted in tens, we'd get to 40 because we're getting really familiar with that now. But we could have shown it on a number line. So that's what I'm going to do now. I'm going to show you. Here's my straightest number line I can draw. We start at zero and our first get count was 10, then 20, 30 and 40. And we can show the number of times we skipped, we skipped counted. One jump, two, three, four. So the number of jumps or the number of skip counts that we did is the same as the number of 10 p coins I would need. So we could stay our stem sentence now. The total value is 40 pence. The value of each coin is 10 pence, so I need four coins. I'm going to read you the next question and I want you to think about what stayed the same and what is different. How many coins do you need to make 40 p in five pence coins? How many coins do you need to make 40 pence in five pence coins? What stayed the same this time? Good. The total amount or total value that we have to get to has stayed the same. It's 40 pence again. But what's different? Good. The coins that we are using to get there. So the value of the coin is changing. We need to count in multiples of five this time and we still need to stop at 40. So you ready? We're going to use our fingers again to count in multiples of five. Five, 10, 15, 20, 25, 30, 35, 40. So I've got to 40. So I stop there. How many fives did we count? Five and three. Eight. Well done. We counted eight, skip step, skip counts in steps of five. Do you remember for the last question, we only needed four 10 p coins. But this time we needed eight five p coins to get to the same total. That's because ... Good, our 10 pence coins are worth more than our five pence coins. I wonder if you can have a think about how much much more. I hope you've come back and I hope maybe your pictures look something like mine. Here are my coins, that I use to get to 40. And here are my skip counts that I use to get to 40. So this next question's a bit harder so I've brought a little helper. This is Terrence. He's a bit shy. He's come to help us with this question. So we're going to read the question first. How many coins do you need to make 16 pence in two p coins? So this time, the total that we're trying to get to, the total we're trying to make us change to 16 pence and the value of the coins we're using has also changed to two pence. Okay? So two things have changed. Okay. So Terrence has made a prediction. He thinks that it's going to take 16 two pence coins to get to the total. There's 16 pence and he thinks he's going to need 16 two pence coins to get to it. Is that what you think? Should we try it out? I'm not sure he's right. Can you guys see what he might've done as a mistake? Oh, Terrence thinks he knows what he's done. Should we try and prove and see? See what has happened. Okay. So we're going to use our fingers. Terrence doesn't have enough fingers so we're going to mine. Okay? And we're going to skip count in twos. Yes twos. Because the value of the coins we're using are two pence. Ready? Two, four, six, eight, 10, 12, 14, 16. So we tracked the number of coins we need. And what's our, how many do we need? We need eight. Well done. Eight. Terrence thinks he knows what he did. What did he forget? Can you remember? Good. He thought he needed 16 coins but it was 16 pence we were getting to. What did he forget? He forgot the value of the coins. The coins we were using were two p so we only needed eight. Well done. We only needed eight, two pence coins. Well done everybody. You're doing brilliantly. So we're back in the shop now and we're going to buy our hat which costs 12 p. Well done for reading that. Good it cost 12 p. Now I know that if I use my one penny coins from down there, my one penny coin purse, I know I can get to 12 pence. I can count that out. But do you remember when we bought the boat? And we bought it with 30 of them, it took ages to count them all out, didn't it? And I don't really want to have to count 12 out this time. It's not very efficient. So I'm going to try using a different coin but I have to make a choice about which type of coin I'd like to use. So I'm going to look at the price of the hat. It costs 12 pence. Now I need to think about when I say the number 12 in my skip counting. What coin can I skip count in and say 12? Can you remember? Yes. I think some of you have got it. Twos. We can count in our two pence and we will say 12 in our skip counting. It's a multiple of two. Should we give it a go and try? Ready. Two, four, six, eight, 10, 12. Brilliant. So we needed six two pence coins. And it didn't take us too long. Did it? Well done. So this time I want to buy the plane and the plane costs 45 pence. So we need to think about that price again. Maybe I'll try buying it with my 10 pence coins. When I skip count in tens, do I say 45? No, I don't. Do I? Okay. So I'm going to have to try a different coin. Can you remember any of those we could skip count in where I would say 45? Five pence. Let's try the five pence coin. Ready? Five, 10, 15, 20, 25, 30, 35, 40, 45. Brilliant. And I wonder if you can see, we got an arrangement of sort of five that looked like the dice there and four that look like a dice there. So all together we know we've got nine, five pence coins. So this is our last practise activity of this section of multiplication. So maybe you can have a go at one of these with an adult in your house. Or maybe even an older brother or sister could have a go at it with you. So you're going to choose one of the objects here from the shop to buy. And you're going to have a think about which coins you could buy it with. So you're going to need to think about your skip counting and which coin would work with which object. Okay? So you're only going to use one coin, one type of coin to buy it. The amount for each toy can be made up in different ways. But I want you to try and find the way that uses the fewest coins for each toy. So there's a few things to think about. You're going to choose an object. You're going to have a think about your skip counting and which coin you could use to buy it. And is that the coin that will give you the fewest coins to buy that toy? Okay. You can go away now and have a go at that activity. The only other thing I need to tell you is that for your next lesson, you're going to need to bring some objects with you. They're going to need to be some small objects that are all the same type of thing. So it might be pieces of pasta or it might be a collection of lego bricks or a collection of spoons. Whatever you want but there need to be about 12 of them and they need to be of a similar type. Thanks very much. Bye-bye.

Further practice buying items with different value coins

Further practice buying items with different value coins

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UnitMaths / Multiplication and money

Maths