To solve word problems

Key Stage 1

Maths

Addition and subtraction (applying strategies)

﻿Hello everybody, it's Miss Sidhu here. We're going to be today, solving some word problems. We are going to use addition, show me the addition sign, and subtraction, show me subtraction, strategies. This is lesson six for the topic of addition and subtraction. You will need a paper and pencil. There are times when you will have to pause the video and have a go at some of the activities yourself. Now let's get started. We are going to look at the key vocabulary. That means our star words, reading through word problems, identifying the key information within a word problem, creating addition or subtraction equations to match the word problem, finding suitable strategies to work out all of the answers, an independent task, and answers to check if you've got them correct. And finally, a quiz to see what we have learned today. Is ready for a star word, star words. I'm going to say the star word first, and then I want you to say after. So my turn first. Part, whole, add, subtract. Can you show me the sign for add? Super. You can also say "plus". Can you show me the sign for subtract? Wow, you were super quick. And now, let's see what we have today. Oh, we've got a word problem in today's lesson. We're going to be using addition or subtraction strategies to work out the word problem that we've been learning over the last few lessons. Word problems are like addition and subtraction equations. Only, we need to read the word problem and then create our own sentence to match it. Let's give it a go. Here is our first word problem. Let's read it together. Mr. Geppetto is collecting paintbrushes in his workshop. He collects 46 in total. 14 of them are taken away to be washed. How many does he have to use? Is this an addition equation or a subtraction equation? Can you shout it out so I can hear? How do you know? Excellent work. You have found out that it is a subtraction equation. Let's find out if we are correct. So, Hmm. We know that Mr. Geppetto has 46 paint brushes. That's one of our key information. So I'm going to circle the number 46. Can you circle that too? Hmm. Now let's have a look at the next bit of information that tells us, it tells us 14 of them are taken away. Fourteen is another key number that we need to circle. Can everybody circle the 14? And there's some other words that help to tell us that it's subtraction. Can you tell me? Super! It's the words taken away. That means we're going to be subtracting. That means a number is going to be fewer and the number's going to be smaller. So this information now tells us that we have a subtraction equation. Now let's write it together. Ooh, subtraction equations. You always start with the whole, the biggest number, it's a 46. Hm, subtract. Can you show me the sign for subtract? Super. 46 subtract 14. Super. I like that you've done the equation as well. Now, what can we use to solve the equation? Let's have a look at some of the things that we have learned in the last few lessons. We have used different strategies and we need to choose one to help us to solve the word problem. We could use a number line and we could get Frodo the frog to help us. We could use our dienes, or we could use our part-whole model. Which one shall we use today? I think we should begin with our number line. Then we can use some of the other strategies for other word problems. Now, great. Now we've chosen that strategy. Let's start. So here I have my number line. Hmm. Let's have a think for a moment. What do I need to remember when I am subtracting on a number line? I know the numbers get smaller when we take away, which means we need to jump backwards when subtracting. So we are going down the number line where the numbers get smaller and smaller towards zero. Okay. So subtraction equation starts with a number. What number does it start with? Super! Forty-six! So let's find the number 46 on our number line. Hmm... Forty-six. I know it's between 40 and 50. Can you point to the number 46? Wow. That was super fast. Let's write number 46 together. Can you get your fingers in the air? Forty-six. Super. Now we need to jump backwards or here we've got, remember I referred to the frog when we're jumping? We need to jump back with 14 times, but we need to remember a little trick when using a number line. Who can remind me how many tens there are in the number fourteen? Can you tell me now? Super. There is one ten in the number fourteen. That means I can jump from 46 all the way to 36. Phew. That saves me lots of time. Thank you. So we've taken away ten and I know 14 has one ten and four ones. So now I need to subtract the four ones. Let's see. Can we do a four jumps going backwards? Well, let's count together. One, two, three, four. Great counting everyone. It looks like we've landed on the number. Can everybody shout it out to me? We've landed on the number 32. Do you agree with me? Let's check if it's correct. Super. We've got the number 32. So 46 subtract 14 is equal to 32. Super. I think we're ready for another subtraction equation or an addition equation. Let's have a look at the next word problem. Ooh. Here we've got another word problem. I'd like you to read the equation and then pause and have a think, what kind of equation it's going to be. Do you think it's going to be an addition equation or a subtraction equation? So I want you to pause, think, and tell the person next to you, if you think it's going to be a addition equation or a subtraction equation. Super. Can you tell me which one you think it is? Or can you shout it out nice and loud? Is it addition or subtraction? I agree. I think it's an addition equation as well. Okay. So like the last word problem, we need to circle the key information. Can you help me? Let's read it together again, and when we come across the numbers, I want you to put your hands on your head and tell me. Let's go. Mr. Geppetto is making new toys. The toy car is 24, oh I love how everybody's put their hands on their head. 24. I know that's one of our key numbers. So I'm going to circle a key number. A toy car is 24 cubes long. A toy bike is eight cubes long. Oh, I love how everybody was super quick with putting their hands on their head when they saw the number eight. That's another key number that we need to look at. What is the total length of the toys? Ooh, let me see where you put your hand on your head. Let's try it again. What is the total? Well done! Everybody has put their hands on their head for the word "total". Total is another way of saying all together and to get the total we have to add. So it's an addition equation. Do you think you can help me write the addition equation? What number would go first? Ooh, our key numbers. Let's have a look. Twenty-four, add eight is equal to... Wow. Thank you for helping me do this, the addition equation. Now, how can we solve it? This time, what strategy could we use? Let's have a go at using the part-whole model. So looking at the addition equation, twenty-four, add eight. So I know twenty-four and eight are the two parts. So we need to put them in the parts boxes. Can you help me? Can you put to the two parts you've got 24 and the other, where does the part go? Super, eight. So we have two choices here. We can use our heads and our fingers to count, or we can use some objects or, or different dienes or number squares to help us to count. I know we could use our hands and fingers. I think that's the quickest one to do now. And everybody can do that from home. So, which is the bigger number, twenty-four or eight? Great 24 is the bigger number because it's further away from zero. As we learned in our previous lesson, it's a two digit number, which means is definitely bigger than eight. And that is only a one digit number. Okay. So let's put 24 in our heads and then we need to continue counting on from 24 until we have eight fingers up as we are adding on. So let's count our eight fingers. So 24. 25, 26, 27, 28, 29, 30, 31, 32. Make sure we've stopped because we've got eight fingers, 32. Let's see, let's count it again. Twenty-four in our heads: 25, 26, 27, 28, 29, 30, 31, 32. Did you get 32, the same as me? Great work, everybody. Let's put thirty-two in the whole. I love how you're doing some excellent math today. Before we do our independent task, I want you to double check our answers, using a different strategy. So we've done number lines. We've used the part-whole model. There's one strategy that we haven't used yet. Well done, we're going to use our dienes. Why don't I give you a clue then? So now we need twenty-four dienes to start with. Can you help me to count 24 dienes? Are you ready? And go! 10, 20. 21, 22, 23, 24. There's our 24 dienes. And now we need to add eight. So we need to count our eight ones. Let's count eight ones. One, two, three, four, five, six, seven, eight, eight ones. Hmm. Well I can see can lots of ones there. Let's count the ones. One, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, twelve ones! We've got more than ten ones. Who can remember what we do when we have more than ten ones? What do we need to do? We need to, ooh, I couldn't hear you then. Can you say it again? We need to, super, we need to regroup. Can we say regroup the ones? So now we have the numbers representing dienes. We can use our knowledge of regrouping to make 10, and that will be easier for us to count. So I've done this to help you to remember to show us how we regroup ten. See here, I've got my 12 ones and we need to regroup. So 12 ones regroup and that makes one 10 and two ones. So 12 ones, let me regroup. Makes one 10 and two ones. So there we have a one 10 and two ones. So now we can regroup. We've regrouped at 12 ones. So we've still got our two tens from 24, One, two. We've got 10, 20, and now we've got 30 from here. And then we've got our two ones. One, two. So there we've got 32. So let's check it again. 10, 20, 30, 31, 32. Well done everyone. Some super work that we've been doing with our math today. Okay, I think that you are now ready for your independent tasks today. In your independent task, you can use any of the strategies. In task one, Mr. Geppetto's house has 16 windows, his workshop has 32 windows. How many windows are there all together? So remember to think about if it is an addition equation or a subtraction equation, and remember to circle or underline the key information. Task two, Anna had 38 coins. She used 17 coins to buy a toy car. How many coins does she have now? So remembering to look at the key information. Task three. Well, we've got another word problem. Mr. Geppetto has been making toy figures. He has made 65 in total. He then sells 32 of the figures. How many figures does he still have? Remember to think is it addition or subtraction? And circling or underlining the key information. We've got one more independent task for you to do today. Ellie baked a cake, mmm, very tasty. She added 40 grammes of flour. Then she added 25 grammes more. How much flour is there now? To make sure you have a think about the word problems, read them super carefully and circle or underline the key information. You can use any of the strategies. You can use a number line. You can use dienes. You might have some objects at home to use. You might want to draw it out like I did here. And you might want to use the part-whole model that's there too. I hope you do some super maths. You might want to use this number line to help you as well. Here are the answers for the word problem for task one. 16 plus 32 is equal to 48. So it's an addition equation. Task two. This time it's subtraction. Task three. It's another subtraction equation. Task four. It's an addition equation. Wow, you have done some super duper math today. I love how you helped me solve all of the word problems. Good job. I hope you had lots and lots of fun. Now, I want you to complete your end of lesson quiz to see how much you remembered and I will see you tomorrow. Bye!

To solve word problems

To solve word problems

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UnitMaths / Addition and subtraction (applying strategies)

Maths