Lesson video

Hi there, my names is Miss Darwish, and our maths lesson today is going to be solving word problems to do with conversions between kilogrammes and pounds.

So, just before we start the lesson, if you can take yourself away from any distractions, that would be great.

Okay, for our lesson today, we're going to be looking at some conversions, and then moving on to word problems, and then there'll be a game of snap, and then a quiz for you to complete at the end.

So if you can just get yourself ready by getting yourself a pen or a pencil, sheet of paper or a notepad, and a ruler, that would be great.

Okay, quick conversion then, you got one kilogramme, two kilogrammes, and 20 kilogrammes.

So, one kilogramme is approximately equivalent to 2.

2 pounds.

Can you say that for me? One kilogramme is approximately equivalent to 2.

2 pounds.

What about two kilogrammes? Two kilogrammes is approximately equivalent to 4.

4 pounds.

Well done if you said that.

So two kilogrammes is approximately equivalent to 4.

4 pounds.

And what about the last one? I'll give you some thinking time.

20 kilogrammes.

20 kilogrammes is approximately equivalent to 44 pounds, well done.

So two kilogrammes, 4.

4 pounds.

20 kilogrammes would be 44 pounds.

You see it's 10 times bigger.

Okay, let's have a look at these three then.

40 kilogrammes is approximately equivalent to, and 50 and 100.

I'll give you a few seconds to write those down, and then we'll go through the answers.

Okay, five more seconds.

Okay, should we have a look? So 40 kilogrammes is approximately, remember these are approximately equivalent to, not equivalent to, they're not exactly the same but around, so 40 kilogrammes is approximately equivalent to 88 pounds.

Well done if you said that, and 50 kilogrammes is approximately equivalent to 110 pounds.

And 100 kilogrammes is approximately equivalent to 220 pounds.

Well done if you got those right.

Okay, let's have a look at a worded problem now.

So, four weightlifters are competing against each other.

The winner is the person with the highest combined total of a snatch and a clean and jerk.

Don't know if you watch weightlifting, so I'm just going to read that through again.

So, we've got four weightlifters, and they're competing against each other.

It's a competition.

The winner is the person with the highest combined total of a snatch and a clean and jerk.

Should we have a look? Okay, so we've got four competitors, Leon, Zach, Ali, and Marvin.

They are our four competitors.

Now, in the table, we can see that Leon got a snatch of 115 kilogrammes and a clean jerk of, clean and jerk of 319 pounds.

And what about Zach? 113 kilogrammes, and what was Zach's clean and jerk? 322 pounds.

And what about Ali? Snatch of 110 kilogrammes, and Ali's clean and jerk? 143 kilogrammes.

And then the last competitor is Marvin, what was his snatch? 115 kilogrammes, and the clean and jerk, 136 kilogrammes.

So, what do we notice here? Some are in pounds and some are in kilogrammes.

Now we're being asked to rank them, but also let's just find the total for each competitor first, and then we can rank them, okay? So we might need to do some conversions.

So as you can see, some of them are in kilogrammes and some of them are in pounds.

So, Ali, let's look at Ali first.

What was his snatch? 110 kilogrammes, and his clean and jerk? 143 kilogrammes.

So can we add those together? Yeah, because it's simple enough just to add the kilogrammes, right? So 110, add 143, is equal to 253.

So Ali's total was 253 kilogrammes, well done.

Okay, which other competitor is easy enough to total and add up? Marvin, good, why? Because both of them are in kilogrammes, so it's simple enough just to add them together.

So we've got 115 kilogrammes for Marvin's snatch, and Marvin's clean and jerk is a 136 kilogramme.

So if we add them up, what do we get? 115 add 136 is equal to 251 kilogrammes.

So now we can actually compare Ali and Marvin.

Who had the higher total? Ali did, Ali had the higher total just by two kilogrammes away, okay? Now let's have a look at Leon and Zach.

So when we look at a worded problem, we sort of just do the easy stuff first, get it out the way, and then we go and have a look at what we need to convert.

Okay, so, let's have a look at Leon.

So his snatch was 115 kilogrammes.

Now, let's look at 115 kilogrammes.

Let's see if we can combine that to pounds.

So one kilogramme is approximately equivalent to 2.

2 pounds.

So what about 115 kilogrammes? So we would do 2.

2 multiplied by 115 which is equal to 253 pounds.

So, now we know that Leon, he had his snatch was 253 pounds.

His clean and jerk was 319 pounds, and if we add them together, we get 572 pounds.

Okay, should we have a look at Zach next? So what was his snatch? 113 kilogrammes, let's see if we could change or convert 113 kilogrammes to pounds.

So again, one kilogramme is approximately equivalent to 2.

2 pounds, good.

So 113 kilogrammes is approximately the same as, how do we work it out? 2.

2 multiplied by 113, which is equal to 248.

6 pounds.

Okay, so now we've got Zach's total, 248.

6 pounds add 322 pounds is equal to 570.

6 pounds.

Now, Leon and Zach's total are in pounds, and Ali and Marvin's total are in kilogrammes, and it's easier to convert kilogrammes to pounds, okay? So what we're now going to do is what? See what Ali and Marvin's total were in pounds.

We know the kilogrammes, we can convert in pounds, easy enough.

Okay, so let's look at Ali's total.

I've got Ali's total, 253 kilogrammes.

So one kilogramme is approximately equivalent to 2.

2 pounds.

So 253 kilogrammes is approximately equivalent to 556.

6 pounds, well done.

Again, to convert between kilogrammes and pounds, we take the kilogrammes, we multiply it by 2.

2.

So 2.

2 times 253 is equal to 556.

6.

Now, guess what we're going to do next.

There's just one competitor left, that is Marvin.

We know his total in kilogrammes and what're we going to do? We're going to multiply it by 2.

2 to find out the exact number of pounds.

So, one kilogramme is approximately equivalent to 2.

2 pounds.

What about 251 kilogrammes? Like I said, we would multiply it by 2.

2 which would equal 552.

2 pounds, and there we go.

Now, what do you notice when you look at them? Do you think you can rank them? Who got the most, who got the least? So who got the least? Marvin, 552.

2 pounds.

And then who got the most? Leon, 572 pounds.

Okay so, if we were to rank them, it would be Leon with 572 pounds, and then after Leon who would it be? It would be Zach, and then? It would be Ali, and then? It would be Marvin, so they're actually already ranked.

Okay, well done.

Now it's time for you to have a go at the independent task for me, if you just give that a go, try your best, come back, and we'll go through the answers and mark them together, good luck.

Okay, welcome back, hope you found that fun and enjoyable.

Okay so, the independent task was a game of snap for you to play with yourself, with your teddies, or with a parent, carer, sibling, your dog, whoever's in the home, whoever's at home that can play with you.

Right, so, always like a game of snap, it's nice and fun.

So we've got one kilogramme is approximately equivalent to 2.

2 pounds.

40 kilogrammes, so let's say you turned over 40 kilogrammes.

How would you quickly convert it in your head? You would say okay, 40 kilogrammes times 2.

2, if I multiply it by two that's 80, so it would be 80 something.

It must be 88 pounds if you turn it over, okay? Same as 544, if you just double it, and then you know.

What's double 500, or what's double 550? Okay, you know how much it's going to approximately be in pounds, that's how I like to do it, okay? So if I'm multiplying by 2.

2, instead, in my head, it might just be easier just to multiply by two or to double it, and then I get, even a rough estimate as to what it might be when I'm playing snap, and then I get really quick and I win.

Okay, if you would like to share your work with us here at Oak National, then please do then ask your parent or carer to share your work for you on Twitter, tagging @OakNational and to use the hashtag #LearnwithOak.

Now it's time for you to go and complete the quiz.

I'm just going to leave you there and just say well done on all the brilliant learning that you have completed today and good luck with the quiz.