# Lesson video

In progress...

Hello, everyone.

Welcome to Maths with Ms. Dobrowolski.

It's really nice that some familiar faces are joining us today.

And if you're new to my class, welcome.

In this unit, we've been studying money and in this lesson, we will be developing our problem-solving skills.

Here is the lesson agenda.

First, we'll be looking at how to approach a problem.

For this lesson you will need a pencil and a notebook.

You may pause the video now and go get these items if you do not have them.

Great! So let's look at how we decide how to approach a problem.

So it looks like we've got some buttons for sale.

Let's see what the problem is asking.

George went to Morrissums and saw some buttons on sale.

He has 50p to spend.

What buttons could he purchase if he wants to spend all of his money? Well, when I approach a problem, the first question I need to ask myself is, what information do I already know? And I already know a couple of things.

For example, I know the whole, I know the total.

And the whole is 50p and that's because, that's what George has to spend and he's going to spend all of his money.

So the whole is 50 pens.

I also know the price of each of the buttons.

Here we can see the red buttons are 10 pens, the yellow ones are 40, the blue ones are 30 and the green buttons are 20.

The next question I have to ask myself is what information do we need to find out? What do we not know yet? And that's how many parts we need to make our whole.

I'm not yet sure what buttons I'll be adding together to make my whole.

That's something I need to figure out.

And finally, I have to ask what problem-solving strategies might help? Well, there's two that I can think of that would be really good for this problem.

I want to first work systematically and that means going in order one by one so I don't miss any potential answers.

I'm also going to use the guess and check method to see if my answers will work.

So for our talk tasks, you need to remember that George wants to spend all of his 50p.

So, when we add our different options together we have to make sure they are equal to 50p.

Now, I like working systematically.

So I'm going to start with the red buttons and go from there.

So what buttons could George purchase? Is it possible for him to only purchase red buttons? Let's see.

If I add 10, five times, that will equal 50.

And p plus 10p plus 10p plus 10 plus 10 is equal to 50p.

So he could possibly buy, one, two, three, four, five red buttons.

Now it's your turn to see what other possibilities exist.

Pause the video here and continue on.

When you're ready, you can resume the video and we'll go over and compare our answers together.

Great! So hopefully you paused the video and you worked out what buttons he could possibly purchase.

Now, again, we said that he could possibly purchase five red buttons.

I also found that he could purchase one red button and one yellow button because 10p plus 40p is equal to 50.

I also found he could purchased two reds and a blue because 10p plus 10p plus 30p is equal to 50.

And he could've purchased three red buttons and one green button because 10p plus 10p plus 10p plus 20p is equal to 50p.

And finally I found that he could also purchase a blue and a green button because 30p plus 20p is equal to 50p.

In this question, it's asking, George's mum gave him an extra 10p to spend at Morrissums. How much money does he have altogether? What buttons can he buy now if he wants to spend all of his money? Make sure you are answering both questions.

You first need to figure out how much money does he have altogether.

Remember George started with 50p and mum has given him an extra 10p.

Then you have to figure out what buttons he can buy now if he wants to spend all of his new money? Remember to work systematically.

Great job everyone! Let's go over the answers.

As you can see, there was a lot of them.

The first one asked, how much money does George have altogether? Remember he started with 50p and then mom gave him an extra 10p.

So 50p plus 10p is equal to 60p.

Now that he has 60p and wants to spend all of it, that changes the buttons or the amount of buttons that he can purchase.

So as you can see, I put all of my answers in the table, 'cause that helped me stay organised.

You could have done this a bit differently and that's fine, but we can still compare answers.

So I worked systematically and I started with the red buttons.

Let's see.

Could George reach his 60 pens spending limit if he bought only red buttons? Yeah, it looks like he could.

Because each red button has a cost of 10p.

If I add 10p, six times, 10, 20, 30, 40, 50, 60, I do reach 60 pens and therefore, George could have bought six red buttons.

Then I wondered if he could buy red and yellow buttons? And it turns out that he could buy two red and one yellow button because 10p plus 10p is 20p, and 20 plus 40 is 60.

Then I wondered if he could buy red and blue buttons? And it turns out if he bought three red buttons and one blue button that would also be equal to 60p.

10 plus 10 plus 10 is 30.

30p plus 30p is equal to 60p.

Then the last combination I could make with red buttons here was red and green buttons.

And it turns out if George bought four red buttons and one green button that would also equal 60p because 10 plus 10 plus 10 plus 10 is equal to 40, 40 plus 20 is equal to 60.

Then I moved on to yellow buttons and it turns out George could've bought one yellow and one green button because 40 plus 20p is equal to 60p.

Finally, George could have bought three green buttons, 20p plus 20p plus 20p is equal to 60p.

He also could have purchased two green buttons and two red buttons because 20 plus 20 is 40, 40 plus 10 is 50, 50 plus 10 is 60p and last but not least, he could have bought three different colours, a red, a blue and a green button because 10p plus 30p plus 20p is also equal to 60p.

I would be really curious to see how you worked it out and what problem-solving strategies you use.

If you'd like to, you could share your work with Oak National, by asking a parent or carer to share your work on Instagram, Facebook, or Twitter, tagging @OakNational and #LearnwithOak.

Don't forget to complete your final quiz before you go off.

It was really nice to see you for this lesson and I hope to see you in future lessons.

Bye.