Lesson video

Hello, I'm Miss Miah and I'm so excited to be a part of your learning journey today.

I hope you enjoy this lesson as much as I do.

You will be able to use a range of strategies to solve division problems. Your keywords are on the screen now and I'd like you to repeat them after me.

Short division, partition.

Fantastic, let's move on.

Short division is a formal method of division often used when dividing any number by a one digit number.

Partition means splitting a number into smaller parts.

For the first lesson cycle, we are going to be comparing strategies for division, and in this lesson you will meet Andeep and Izzy.

Let's get started.

So when you solve problems to do with division, you need to decide which strategy will be most efficient.

And on the screen you can see three strategies here.

So you've got the informal method or mental strategies, partitioning using a part whole model and the use of short division, which is a formal method.

So in this lesson, you will learn to choose the most efficient method for division.

And that's because as mathematicians, we want to choose the method that is most efficient that will get us to our answer the quickest.

Andeep and Izzy are comparing strategies for this division equation, 84 divided by 4.

Andeep says he's going to use short division because it's the quickest and easiest.

Izzy says that there are probably more efficient ways.

So let's have a look at what they might be.

So first off, it's a two digit dividend divided by a one digit divisor.

Now the digits in the dividend are multiples of the divisor.

So you can partition the dividend into multiples of the divisor.

So for example, you can use the partitioning strategy to do this.

So in this case, 84 has been partitioned into 80 and 4, 80 divided by 4 is 20, 4 divided by 4 is 1.

And then you add the partial quotients, which are 20 and 1, which gives you 21.

Or you can use a mental strategy.

So Izzy says that she knows dividing by 4 is the same as halving and halving again.

So the quotient is 21.

So rather than getting a pencil and paper out and starting your short division, using a mental strategy is definitely more efficient.

And often there is not a single best approach.

So back to you, which method would you pick for this division equation? And I'd like you to justify your thinking to your partner.

If you don't have a partner, you can write down your justification on a piece of paper.

You can pause the video here.

So what did you get? Now, a mental strategy would've been best because you should know your tables and you could use the inverse to calculate 48 divided by 6.

Partitioning is also a good method.

Someone may have chosen to use short division if they would've wanted to record their partial quotients.

Let's move on.

Andeep and Izzy are comparing strategies for this division equation, 794 divided by 6.

So on the screen you can see Andeep's method and Izzy's method.

So Andeep's used short division and Izzy's used the partitioning strategy.

Andeep says that he's used short division because the dividend cannot be partitioned into multiples of the divisor.

Izzy says that she's used partitioning because she found multiples of 6 and then divided each part by 6.

So I'd like you to think about which method you prefer and why.

Back to you, which division strategy would be most efficient for calculating 483 divided by 6? And I'd like you to justify your thinking to your partner.

You can pause the video here, off you go.

So what did you get? A mental strategy would be more efficient, this is because 6 multiplied by 8 is 48.

So 6 multiplied by 80 is 480.

There are 3 more, so there is a remainder of 3.

So the quotient is 80 remainder 3.

Now sometimes you may come across questions where the dividend and the divisor are the same.

For example, 4 ice creams were divided equally between 4 children, how many ice creams did each child get? So our division equation is 4 divided by 4.

You can make 4 groups of 1, that's 1 each.

So 4 divided by 4 equals 1.

Each child gets 1 ice cream each.

Anything divided by itself is one and that is a key rule, I'd like you to remember that.

Therefore, it's best to use a mental strategy for this type of question.

Back to you, I'd like you to pause the video here and when you're ready, click play.

So how did you do? You should have got B as your answer.

And that's because there are 5 ice creams that are shared between 5 children.

So the division equation is 5 divide by 5, each child will get 1 ice cream.

Back to you again, I'd like you to fill in the missing gap.

So how did you do? Anything divided by itself is one.

Now sometimes you may come across a question where the divisor is 1.

So for example, 6 cakes are shared equally between 1 box.

That means our division equation is 6 divided by 1.

So 6 divided by 1 is equal to 6.

There are 6 desserts in 1 box.

This is a key rule here, anything divided by one is itself.

A mental strategy is best for this type of question.

Back to you, which strategy would be best for the division equation 365 divided by 1.

You can pause the video here.

So what did you get? A mental strategy.

And that's because you know that anything divided by one is itself.

Your main task for lesson cycle one.

So question one, you're going to be completing the table that you can see on your screen by justifying why you have picked each strategy and finding the quotient.

You can pause the video here, off you go, good luck.

So how did you do? This is what you should have got.

We're going to have a look at a couple of the questions in more detail.

So let's have a look at question one, 484 divided by 1.

Now the strategy that you should have chosen should have leaned towards the mental strategy, and that's because you should remember that anything divided by one is itself.

So the quotient would be 484.

Now let's have a look at the last question.

618 divided by 7.

Now you should have leaned towards short division and that's because the digits in the dividend are not multiples of the divisor.

So the quotient that you should have got is 88 remainder 2.

Onto our second lesson cycle.

For this lesson cycle, you are going to be applying strategies to solve problems. Now when you solve problems to do with division, you need to decide which strategy will be most efficient.

The language in a worded problem can help us find the division equation.

For example, split and cut often means a division question.

Seeing equal parts usually means that you have to divide.

Sharing and dividing means that your operation will be to divide.

Over to you.

What is the equation and what word would help us? So how did you do? You should have got 135 divided by 5, and the word that would've helped us is split because that usually means to divide.

Now you can think about what is known and what is unknown.

Bar models can be used to represent a worded problem.

What do I know, what don't I know and can I draw it? So these are the parts that are going to form your bar model and help you with your mathematical thinking.

So Andeep has a collection of 135 mini figurines.

He wants to split them between 5 of his friends.

How many figurines will each friend get? Well, you know that the whole is 135.

You know that 135 figurines will be divided into 5 equal parts as Andeep is sharing between 5 of his friends.

You do not know the value of each part, which is how much each friend will get.

Now bar models can be used to represent a worded problem.

Now here we can see a bar model to represent the worded problem.

Now because there are 135 figurines altogether, that's our whole and that's placed at the top.

It's being split into 5 equal parts.

We do not know the value of each part.

So that is what we're calculating.

Over to you, tell your partner what is known and what is unknown in this worded problem.

Off you go, you can pause the video here.

So how did you do? Well, we know the whole is 284, which is how many cupcakes there are.

We know the divisor is 4, which is how many cupcakes fit in 1 box.

We know the size of each group or box, we don't know the number of groups or number of boxes.

If you got that, well done, you can give yourself a tick.

Back to you again.

So this time you're going to draw a bar model to represent this worded problem.

You can pause the video here and click play when you're ready to join us again.

So how did you do? This is what you should have got.

So there are 555 experience points altogether, that's our whole, so we would've placed that at the top.

Now we're dividing it between 5 of his characters.

So here at the bottom we can see that it's been split into 5 and we need to calculate with what each part represents.

Onto your main task, you're going to be using an efficient strategy to solve each problem.

You may want to represent each using a bar model to help you with your calculation.

So for question one, Izzy is collecting figurines.

She has collected 125 altogether.

She now wants to share them equally between 5 of her friends.

How many figurines does each friend get? Question two, 987 cookies are packed in boxes of 3.

How many boxes are needed to pack all of the cookies? Question three, 483 pencils are shared between 6 classes.

How many pencils will each class get? For question four, for every 7 tickets sold, there is 1 golden ticket.

If there were 595 tickets sold in a week, how many golden tickets were given out? For question five, eggs are split into baskets of 6.

If there are 271 eggs, how many baskets will be needed? Will there be any eggs left over? Now before you get started, do remember to highlight the keywords and figure out what the calculation is first.

You can pause the video here, off you go, good luck.

So how did you do? Let's get ready to mark.

So we will look at question one and two in more detail and then we can mark the rest.

So for this first question, we know that there are 125 figurines altogether.

So that is the dividend.

Now the divisors is 5 because that's how many friends there are and that's how many we are dividing by.

So our division equation is 125 divided by 5 and that is 25.

Each friend will get 25 figurines each, the quotient is 25.

If you got 25, well done, give yourself a tick.

Now for question two, our dividend is 987 and that's because that's the whole.

Now the divisors is 3 because that's how many cookies are packed in each box.

We need to figure out how many boxes there will be altogether.

So that means our division equation is 987 divided by 3 and you should have got 329 boxes as your answer, which means our quotient is 329.

You can pause the video here to mark your work, click play when you're ready to join us.

If you manage to get all of those questions correct, well done.

It means that you're able to recognise the division equation and use short division to support you with your calculation.

Let's summarise our learning for today.

So today you learned to use efficient division strategies to solve problems. You can now look at the dividend and the divisor to decide which strategy is the most effective and explain why.

You're able to use partitioning if the dividend can be partitioned into multiples of the divisor.

And lastly, you can use short division if the dividend cannot be partitioned into the multiples of the divisor.

Well done, we've finished this lesson.

I'm really glad you joined me and I can't wait to see you in the next one.