How to Divide Fractions

How to divide fractions

This series of 3 minute math is designed as a quick reminder for some of the main topics. I hope they help to provide a focus and a way forward. If you need any more detail please search the site or contact me – always pleased to answer any questions!

All the very best with your studies.

Transcript from the video:

“Hello and welcome to Three Minute Math. This is all about dividing fractions, so let’s jump right into a question.

We’ll take something like…

six elevenths divided by twelve thirty-threes

When we’re dividing fractions, one of the tricks that we can use is to ‘flip’ the numbers and actually multiply, I’ll show you what I mean…

We keep the six elevenths but then we multiply and flip the twelve thirty-threes, so we end up with

six elevenths multiplied by thirty-three twelfths

(this is a trick we always use for dividing fractions).

Next, I’m going to reduce these numbers to make them a little bit easier to deal with…

So if I divide the top by six I get one and the bottom by six I get two

then the bottom by eleven giving me one and the top by eleven giving me three

so now if I multiply…

one times three is three divided by

one times two is two

this results is the top-heavy fraction:

two over three

… so I’ll convert this back to a mixed number which is

one and one half

which is the answer to this question.

(If you need to know how to perform the multiplication stage, take a look at the Three Minute Math multiplying fractions video).

Okay, so let’s make this a little bit trickier now by adding some whole numbers into the question…

three and seven elevenths divided by

two and twelve thirty-threes

this is more typical of a GCSE exam question and the first thing we need to do is convert it to top-heavy fractions.

So, converted our fractions become:

forty elevenths divided by seventy-eight thirty-threes

Exactly as we did earlier, we turn this second fraction upside down and multiply…

…forty elevenths multiplied by thirty-three seventy-eights

Now we’re going  to reduce these numbers to make them easier to deal with:

Dividing the bottom by eleven gives me one and the top by eleven gives me three

…then I’ve got forty and seventy-eight.  Seventy-eight is a big number to deal with!

However, I can reduce this first number by two which gives me twenty and the seventy-eight becomes thirty-nine.

This is pretty good but I can reduce even further!

If I divide my three by three I get one, and then divide my thirty-nine by three I get thirteen, so now I have:

twenty ones multiplied by one thirteenth which is…

…twenty thirteenths

which converted back again is

one whole and seven thirteenths

I hope that’s been helpful to you, please do have a look at some of the other videos and I’ll look forward to seeing you inside the next three minutes.”

 

 

Watch the video on YouTube – How to divide fractions