Change from a pound

Key Stage 1

Maths

Money

How many 10p coins do I need to make 20p?

﻿Hello everyone, and welcome to maths with Ms. Dobrowolski, in this unit we're studying money. And in today's lesson, we'll be learning all about how we can make change from a pound. Today's lesson agenda is as follows, first we'll practise paying using exact coins, then we'll have our talk task, then we'll be finding change from a pound followed by our independent task. For this lesson, you will only need a pencil and a notebook or something to write on. If you don't have these items, pause the video now and go get them. So, let's review really quickly, how many pennies are equal to one pound? Have a think and then tell your screen. Good, so 100 pence or 100 pennies are equal to one pound, so we would need all of these pennies to equal this one pound coin. Now, this is really useful for us because we're going to need this knowledge when we start making change. So everyone my turn, your turn. One pound is equal to 100 pence, well done. Great, so here I have some money in my purse. How much money do I have in my purse? Well, we always start with the coin with the greatest value. So, we're going to add all of our coins, but we're going to start with the coin with the greatest value, which in this purse is 50. Okay, so 50p, plus 20p is 70p 70p plus 20p is 90p and 90 plus 10 is 100p and 100p is equal to, one pound. So really in my purse, I have one pound. Okay, I've taken my purse with my one pound, and I've gotten to the shop. If I buy a pencil, what coins should I give the shopkeeper? Well, let's see, it looks like the pencil, has a price of 10p. Do I have a coin in my purse that has a value of 10p? Well of course I do. So I'm going to pay with my 10p coin. I've given it to the shopkeeper, it's no longer in my purse. So, how much money is left in my purse after I buy the pencil? Let's see how much I have left, 50 plus 20 is 70p, 70p plus 20p is 90p. So I only have 90p left in my purse. I started with 100p and then I gave away 10p, which left me with 90. We can use, a whole part model to help us understand this. So I know my whole is 100p, because I said, I started with one pound in my purse, which is equal to 100p. Then, my part that I gave away is 10p. After I gave away 10p, whatever is left, is the rest of my part. So, I took away 10p so 100p take away 10p is equal to 90p and that's what I had left in my purse. Let's try this again, I went to the shop, and I bought an apple, what coin should I give the shopkeeper? Have a look. Ah, the price of an apple is 50p, do I have a 50p coin in my purse? Yes, I do. So, I'm going to give the shopkeeper, my 50p coin. I had 100p, and I gave away 50p, how much money is left in my purse? Let's count now that my 50p is gone. 20 plus 20 is 40, 40 plus 10 is 50. So I only have 50p left in my purse. So, let's use the whole part model to help us understand what happened. Remember, I started with 100p, so that was my whole, I gave the shopkeeper 50p, that was a part of what I had that's a part of my whole. So I gave away 50p, we made it disappear, there it goes. And whatever I'm left with, is what's in my purse. So we said, that 100p take away 50P is equal to 50p. And that was right, because when we counted our coins without the big 50p coin, that's what we had left, was 50p. Okay, now I'm showing you a different purse. Let's count how much money I have in my purse now. Remember, we start with the coins with the greatest value first. So, we'll start with 50, add the 20, then the 10, and then the five p, followed by the two, and then the one. So follow along with me and make sure you're counting and adding as I'm adding in counting. So 50 plus 20 is 70, 70 plus 10 is 80, 80 plus 10 is 90, 90 plus five is 95, 95 plus two is 97, 97 plus two is 99 and 99 plus one is 100p, or, what's another way we can say that? One pound, well done. So I have one pound or 100P in my purse. If I buy a lolly for five pence, what coin should I give the shopkeeper? So do I have a five p coin? Yes, I do, I'm going to give that to the shopkeeper. And it's gone. Now, how much money is left in my purse? Let's take a look. 50 plus 20 is 70, 70 plus 10 is 80, 80 plus 10 is 90, 90 plus two is 92, 92 plus two is equal to 94, 94 plus one is equal to 95. So I started with 100 pence, I gave away five pence, I should have 95 pence left, but let's again, use our whole part model to help us understand that. Well, my whole again is 100p because that's what I started with. I gave away the five p coin, it's not here anymore. So my five p has to disappear, that part has to disappear. And what I'm left with, is going to be what's in my purse. So we said, 100p take away five p was equal to 95p. And when we counted my purse again, that's exactly what we had, was 95p. Great, it is now time for your talk task. So, what I would like for you to do in this talk task, is I would like for you to tell me how much money is left over after you pay for each of these items. So let's do the first one together so that we're all clear. It's also really important that you're saying all of this out loud when you're completing the talk task, because we need to be using mathematical language. So, I would like to buy an apple that costs 50P. I will pay with a 50P coin. So I see that because I see that there's a 50P coin. Now, I have left after paying for my item. So I figured that out by counting the rest of the change without, or the rest of the coins, without counting the coin I just paid with. So now I'm going to count my purse again, but I won't be counting the 50 pence coin I just paid with. So, I have 20 plus 10 is 30, 30 plus 10 is 40, 40 plus five is 45, 45 plus two is equal to 47, 47 add two is equal to 49 and 49 plus one is equal to 50. So I have 50p left after paying for my item. So now your turn, pause, the video, complete the talk task for all of the other items to work out the change you would have after paying for them. When you're done, make sure to resume the video and we'll go over the answers together. Great, so hopefully you've completed the top task and you're ready to review. So, we already completed the apple, when I bought the chocolate bar that cost 20p, I paid, with a 20p coin, so then I had 80p left after paying for my item. When I bought the lollipop that cost five p, I paid with a five p coin, and I have, 95p left after paying for my item. When I bought the pencil that costs 10p, I paid with my 10p coin. I have 90p left after paying for my item. When I bought the candy, that costs two p, I paid with a two p coin. I have 98p left after paying for my item. And finally, when I bought the candy that costs one p, I paid with a one p coin, so I had 99p left after paying for my item. Well done, everyone. What would happen if I try to pay for an 80 pence item with one pound, with a one pound coin? This is tricky because one pound is worth more than 80p, it has a greater value, and it's not like I could just split my coin up, break it up and say to the shop shopkeeper, hey, here's 80p from my one pound coin, That's not possible. So I need to get change because I can't split my coin. So how can I get some kind of change? Well, we can use this whole part model to help us, let's work out how much change I would get from one pound. I know that my whole is one pound, so I'll fill that in, in the whole, but, instead of writing one pound, I'm going to write that one pound, is equal to, that's right, 100 pence. So, I'm going to put 100 pence, in my box here, because it's going to make it much easier. Do you see, how the item it has a price in pence? I want to make sure that everything I put into each of these boxes, has the same, has pence. So, 100 pence is my whole, I know, that the cost of the item is 80P, so that's my first part. 80 pence is my part, okay? How much more do I need to make a total of 100 pence? Well, one way to work out change is by counting up. So I'm going to show you how I count up from 80p, and I want you to watch and count with me. So, I'm going to start at 80, because that's where I started when I paid, I need to count all the way up to 100. Every time I count, I'm going to put a tick mark that looks like that. So, I need you to make sure that you're counting along with me from 80 to 100 and you watch my ticks. So, we start with 80 and we go, 81 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100. Now, in order to work out how much change I would get, I'm going to count the amount of ticks. And, once I've counted that, that number will be equal to my change. So again, count with me and this time, I'm going to circle each one so I don't double count by accident. So, one, two, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. So that means I had 20 ticks, so my change is going to be 20 pen. So as we saw from the ticks, if I pay for an 80p item with one pound, my change will be 20p. And I know this is correct because 80 plus 20, is equal to 100. Let's try another example. So this time, let's work out how much change I would get from one pound after buying a rubber that costs 60P, there's a 60p on the price label here. So I know, that one pound is equal to? That's right, 100 pence. So 100 pence is my whole. My part, is going to be the price of the rubber, which is, 60 pence. And then my other part here is my unknown value, that's what I'm going to figure out. So, again, we're going to figure out the change together by counting up. So again, make sure you watch and count with me. So, remember, we started 60, and we're going to count all the way up to 100, because that's our whole. So I'll make a tick every time I count, it's really important that you're counting along with me. So everyone, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71 72, 73, 74, 75, 76, 77, 78, 79, 80, 81 82, 83, 84, 85, 86, 87, 88, 89, 90, 91 92, 93, 94, 95, 96, 97, 98, 99, 100. And now, we count how many ticks I made, but I'm also going to circle each tick as I count it, so I don't double count by accident. So count with me, 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, 31, 32 33, 34, 35, 36, 37, 38, 39 40. I had 40 ticks, so I know my change is going to be 40. So, as you can see from the ticks again, if I pay with one pound for a 60 pence item, my change will be 40 pence. So, it is now time for your independent task, but let's go together the first time, just so we know what to do. Great, so step one, we're going to count up from the price to one pound. Oh, I forgot to tell you what the point of this is, the point of this independent task, is to find the change for each item after paying with one pound, so you have to pretend that for each item that you're buying, you're paying with one pound. So step one is to count up from the price to one pound. So in the first example, this bag of apples has the price of 95p. So I count from 95 to 100 and I make my ticks. So step two is to make the ticks, so I went 95, 96, 97, 98, 99, 100. Step three, is the number of ticks is the amount of change you receive, so make sure you count your ticks. One, two, three, four, five. My change would be five pence. So if I paid with one pound for an item that costs 95p, my change would be, five pence. So, now it's your turn, make sure you pause the video, complete your independent task, and when you're finished, resume the video, so we can go over the answers. Great, so hopefully you've paused the video, you've completed your independent task and you're ready for the answers. So the change for the pen would have been 25p because 100 take away 75 is 25. For the pencil, 100p take away 60P would have been 40P, and the ice cream, 100p take away 65p is 35p. For the comic, 100 pence take away 85 pence would have been 15 pence, that would have been your change. For the rubber, 100 pence take away 50 pence, is equal to 50 pence. For the lemon, 100 pence take away 80 pence would have left you with 20 pence of change. And finally, for the bag of bananas, that cost 99 pence, 100 pence take away 99 pence leaves you only with one pence change. Well done, everyone. This was a really good lesson and really good effort on your part. If you'd like to, you can share your work with Oak National by asking your parents or carer to share your work on Twitter, tagging @OakNational and #LearnwithOak don't forget, you also have to complete your quiz, so go ahead and do that now. It was really great to see all of you and I hope to see you next time, bye now.

Change from a pound

Change from a pound

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UnitMaths / Money

Maths