Lesson video

Hi, I'm Mr.Chan, and in this lesson, we're going to be learning about simplifying fractions.

Let's look at simplifying fractions.

So here we've got a fraction model, that's split up into twentieths.

The whole has been split up into twentieths, and we've got four shaded in.

So that fraction model there we can see, is representative as four twentieths.

What we've got to try and do when we're simplifying is rewrite that fraction in it's simplest form.

And what that means is, can we write that in a more straightforward, simple form and what we can think about with this example is possibly splitting it up into fifths.

As such.

So with this question, four twentieths, if we were to simplify this as simply as possible, we could say that four twentieths simplifies to one fifth.

A nice way to think about that is as well, what's happened to the denominator, what's happened to the numerator.

Well both have been divided by four.

Here's a question for you to try.

Pause the video to complete the task, and resume the video once you've finished.

Here are the answers.

What we notice with this question, is that the whole has been split up into different number of parts, however, the whole is the same size in parts a, b, and c.

So why we see that all the rectangles have the same fraction shaded in, is because they're equivalent, and what we've done going from a to b to c, is we've simplified the fraction in each step, and part c has the fraction fully simplified.

Here's another question for you to try.

Pause the video to complete the task, resume the video once you've finished.

Here are the answers.

In this question, we've got write this fractions in the simplest form.

So let's look at part c.

In part c, we have a fraction ten fifteenths.

Because there are ten shaded after fifteen parts.

What we can do is imagine that ten fifteenths as thirds, and in that case we would have two thirds shaded, and that would represent the fraction in its simplest form.

Lets look at simplifying fractions where we don't have to draw a fraction model each time.

Previously we looked at simplifying four twentieths, into its simplest forms, writing that as one fifth.

Notice that with the numerator and denominator, what's actually happened is that we've divided the denominator and the numerator by four.

Four divided by four gives us one.

Twenty divided by four gives us five, and that is quite an efficient way to simplify fractions.

Let's look at another example, twelve eighteenths.

Twelve and eighteen, both even numbers, we can divide both denominator and numerator by two.

That gives us a simplified fraction of six ninths.

However, we've got to be careful, because six ninths is not that fraction simplified fully.

It is not in its simplest form.

So with six ninths, we can further simplify.

I do know that six and nine have a factor of three, so we can divide numerator by three, we can divide the denominator by three, to leave a fully simplified fraction, two thirds.

I now know that that's fully simplified, because there are no common factors for two or three.

We could have started with twelve eighteenths, and more efficiently divided the numerator by six, and divided the denominator by six, to leave the same answer fully simplified again, two thirds.

Here's a question for you to try.

Pause the video to complete the task, resume the video once your finished.

Here are the answers.

In this question, it's important that you make sure you simplify fully.

An example of this would be part d.

In part d, you may have divided the numerator, and the denominator by two, to leave an answer, six ninths.

However, that's not fully simplified, because you could simplify that further, to simplify to two thirds.

A more efficient way is to start out by dividing by six, in this question.

So you would've divided the numerator by six, to leave two, and divided the denominator by six, to leave three, and a fully simplified fraction, two thirds.

Hopefully, you did well with those.

Here's another question for you to try.

Pause the video to complete the task, resume the video once you have finished.

Here's the answer.

As you can see, James and Katie have simplified the fraction in different ways, and there's no preferred better way.

However, there's probably, you could say, a more efficient way.

But the overall outcome, is that they both got the same answer, and how they've simplified their fractions, as you can see in the answer showed.

That's all for this lesson.

Thanks for watching.