Lesson video

Hi everyone, Ms. Hill here.

Welcome back to your unit on Number Sense.

Today, we're going to be using our number knowledge to solve word problems and using bar models.

I'm really excited because it's a really exciting way to use all of our knowledge that we have.

So while we get started, put on your hats.

[whoosh] Tighten your ties.

[pantomimes tying a necktie] Tell the computer, "Now I'm a mathematician." Let's get started with our learning.

Here is our lesson agenda for today.

First off we're going to do our Star Words.

We're going to be using bar models to solve word problems, and we're going to do a little bit of practise with this as it can be a little bit tricky, before moving on to our independent task and quiz.

But before we get started, please make sure you have a pencil, a piece of paper, and a ruler.

If you need to get any of these things, please pause the video.

Great.

Let's get started with our star words! Now, you know when I say it, you need to say it back to me and copy with me.

Copy me with the actions.

Let's get started.

More.

Fewer.

Less.

Difference.

Known.

Unknown.

Add.

Subtract.

Can you show me "Known?" Show me "Unknown." Show me the "Difference." Brilliant.

Now let's remember to use these star words.

You might have to give me a gentle reminder too.

So here we have our first word problem.

What I'd love is if you can read it along with me.

Sam and Jo are measuring some wood to build a bench.

Sam has a plank of wood, which measures 96 centimetres.

And Jo has a plank of wood that measures 21 centimetres.

How much longer is Sam's plank of wood than Jo's? So with this question, we know that we can identify the Known facts and we can also identify the Unknown.

So the Known fact is that we know that Sam has a plank of wood, which is 96 centimetres, And Jo has a plank of wood that measures 21 centimetres.

The Unknown is the difference between the two lengths, and we can use a bar model.

Here you can see, you can have the whole, which is 96 centimetres.

So this is the Known fact of how long Sam's plank of wood is.

And Jo's plank of wood is here, which is also a Known fact, which is 21 centimetres.

However, the unknown fact, that's the one with the question mark.

For our second word problem.

Let's read it together.

Let's do it our whispery voices.

An apple weighs 58 grammes and a banana weighs 19 grammes more.

How much does the banana weigh? Have a think? Which is the Known fact, and the Unknown fact? Well, here we can see our apple.

We know that the apple weighs 58 grammes and we know the banana weighs 19 grammes more, but we don't know how much the banana weighs.

So we would need to add the two totals together to get the banana's weight.

For your mini task today, you're going to be matching up the bar models of the questions.

As you can see, I've done the first one for you.

An orange weighs 62 grammes and a peach weighs 34 grammes.

How much more does the orange weigh than the peach? You can see if you have the orange, which is the total number of 62 grammes.

We have our peach, which is 34.

And then the difference, which is the Unknown fact.

You need to match up the next three bar models with the questions.

Pause the video! Brilliant.

Well done.

Let's get through them together.

Lisa and James are building a swing.

Lisa has 62 centimetres of rope.

James has 34 centimetres more.

How much rope does James have? So here we can see how much Lisa has, and we can see that James has got 34 centimetres more.

So we'd add these two together to get the whole.

A can of fizzy drink costs 60 pence and sweets cost 30 P.

less than the fizzy drink.

How much do the sweets cost? So here we have a 60 pence and we need to subtract 30 pence to get our Unknown fact.

Which means Max has 60 millilitres of medicine, Ben has 30 millilitres medicine.

How much less medicine does Ben have than Max? So you have Max' amount here, Ben's amount here.

And the Unknown here.

Yeah, well done everybody.

Make sure you tick and fix before moving on.

And here we have words problem 1.

Sam and Jo are measuring some wood to build a bench.

Sam has a plank of wood which measures 96 centimetres.

Jo has a plank of wood measuring 21 centimetres.

How much longer is Sam's plank of wood than Jo's? So here we've already identified the Known and Unknown facts that belong in our bar model, so now it's time to solve it.

So if I know that two add seven is equal to nine, example: two add seven is equal to nine.

Then I know that 20 add 70 is equal to 90.

So this number must stop with seven, so be seven 10s.

If I know that one add five is equal to six, then when I add 70 add 5, it's equal to 75.

Therefore, this missing number must be 75 centimetres.

Please make sure you remember to use the unit of measurement.

So in this case, it is centimetres.

So my steps to success, we read the question, we identified and underlined the key information.

We did that before and we created our bar model.

We also use our calculation strategy, and then we answered the question together.

So let's do the next one.

Here is word problem number 2.

An apple weighs 58 grammes and a banana weighs 19 grammes more.

How much does the banana weigh? So our Known fact is that the apple weighs 58 grammes.

And we know that banana weighs 90 grammes more.

So we need to add the two together in order to find the total weight of our banana.

So here we have our bar model, which shows 58 grammes of the apple, and the banana that weighs 19 grammes.

And we need to find the total.

I'm going to use my number knowledge here.

Five add one is equal to six.

Then I know that 50 add 10 is equal to 60.

Eight add nine is equal to 17.

17 grammes add 60 grammes is equal to 77 grammes.

Therefore, the banana weighs 77 grammes.

Here's our third number problem.

Our word problem.

A toy football weighs 75 grammes and a toy basketball weighs 23 grammes more.

How much does the football weigh? Here you have the steps of success.

Pause the video and find out the answer! Great job! So here we have our bar model.

We've got our football that weighs 75 grammes and our basketball that weighs 23 grammes.

In order to find out how much the football weighs-- sorry, the basketball weighs, we need to add 75 and 23 grammes together.

If I know that seven add two is equal to nine, then I know that 70 add 20 is equal to 90, and I also know that five add three is equal to eight.

So when I add 90 and eight together, the total is 98 grammes.

For your independent tasks today, you are going to be answering these six questions and drawing your own bar models.

So remember to pause the video before moving on.

Super job, let's have a look at these answers together.

Ellie and Becky baked a cake.

Ellie used 67 grammes of flour and Becky used 34 grammes of flour.

How much less did Becky use than Ellie? So we need to find the difference between 67 and 34, and the answer is 33 grammes.

Question two.

Anna has 27 pounds.

Jake has 14 pounds.

How much more money does Anna have than Jake? So here we can see Anna has 27 pounds, and Jake has 14 pounds.

We need to find the difference between the two, and the answer is 13 pounds.

Question three, Lisa and James are building toy trains.

Lisa's train is 80 centimetres long and James' train is 33 centimetres shorter.

How long is James' train? So we need to find the difference between the two, and the answer is 47.

Question four.

A packet of biscuits cost 45 P.

and a bottle of water costs 39 P.

more.

How much does the water cost? Here we have our packets of biscuits at 45 P.

and the bottle of water costs 39 P.

more.

So we need to add the two together in order to find the difference.

And here we can see the answer is 84 P.

Question five.

Jay's paddling pool has 90 litres of water.

Sally's paddling pool only has 78 litres of water.

How many more litres of waters in Jay's pool than Sally's? So here we have Jay's paddling pool and Sally's paddling pool.

We need to find the difference between the two, which is 12 litres.

And finally, question six.

Alice walks 58 metres to her bus stop, but she walks 17 metres less to school.

How far did she walk to school? So again, we have the metres to the bus stop, metres to school, and then we find the difference between the two, which is 41.

Well done, everybody.

That was a tricky lesson today.

You should feel very proud of yourselves.

Remember to give yourself a one, two, three, well done me! If you'd like to, please ask your parents or carer to share your work on Instagram, Facebook, or Twitter tagging at Oak National and hashtag Learn with Oak.

I've had a super time with you today and I can't wait to see some more learning.

But before you go, make sure you remember to complete the quiz.

See you again soon.

Bye!.