Fractions help

Purple Mountain

Hi all.
I'm a little stuck with Junior's 4th class Maths.
It was never my strong subject.
I'm having problems explaining my method so I'm looking for someone to put this into explanatory terms for me please.

Eg. 4/5 of 20.
In my day, I was told to divide by the bottom and multiply by the top.
He says this doesn't make sense to him but he obviously wasn't listening enough to catch the alternative method!

zoe 3619

Purple Mountain wrote: »

Hi all.
I'm a little stuck with Junior's 4th class Maths.
It was never my strong subject.
I'm having problems explaining my method so I'm looking for someone to put this into explanatory terms for me please.

Eg. 4/5 of 20.
In my day, I was told to divide by the bottom and multiply by the top.
He says this doesn't make sense to him but he obviously wasn't listening enough to catch the alternative method!

Work out what one 5th is (divide by 5),then get 4/5 by multiplying by 4.your method is fine,but maybe needs breaking down into smaller steps so that he can see the logic?

kandr10

Purple Mountain wrote: »

Hi all.
I'm a little stuck with Junior's 4th class Maths.
It was never my strong subject.
I'm having problems explaining my method so I'm looking for someone to put this into explanatory terms for me please.

Eg. 4/5 of 20.
In my day, I was told to divide by the bottom and multiply by the top.
He says this doesn't make sense to him but he obviously wasn't listening enough to catch the alternative method!

Try drawing simple pictures. Draw a rectangular bar and divide it into 5 parts for the fifths. The whole bar, ie 5/5 represents 20. Then explain that you need to find 1/5 before youncan find 4/5. By looking at the picture, explain that you divide by 5 since you started with 5 and you want to find one. Once you know 1/5, you can fill in it’s value in each of the boxes. Then by counting or, hopefully, multiplying, he should be able to find 4/5.

You could rephrase the problem either. Set out 20 pieces of pasta or 20 sweets or whatever. If the set is divided between 5 people, how many will one person get. Then how many will four get.

Using real materials, then pictures eventually leads to the conclusion that you divide by the bottom and multiply by the top. If they don’t reach that conclusion on their own, the rule makes no sense and they don’t know when to apply it.

I try to get kids to write their answers systematically, so
5/5 = 20
1/5=
4/5. =

Hope that helps and it’s not just clear as mud!

Purple Mountain

Thanks both.
I was jumping the gun with him altogether!
No wonder he looked exasperated..

kandr10

Purple Mountain wrote: »

Thanks both.
I was jumping the gun with him altogether!
No wonder he looked exasperated..

Fractions do that to kids for whatever reason!

Purple Mountain

kandr10 wrote: »

Fractions do that to kids for whatever reason!

And mammies!

Lisha

Lego blocks, pizza/cake drawings are what I use to try and demonstrate fractions.

You have to break it down into something the can feel/touch .

Another one is draw like a thermometer, full being a unit or 100%.

So if I had 1/5, colour it in, and increase the colours to get to 4/5 etc .

I had to use a lot of cutlery to explain long division to my poor brother. He got it eventually. A few years later he realised he very dyslexic with dyspraxia.

spurious

If you can, have a quick chat with his teacher and try stick to the method they are following. It's easy confuse them.

Del2005

Purple Mountain wrote: »

Hi all.
I'm a little stuck with Junior's 4th class Maths.
It was never my strong subject.
I'm having problems explaining my method so I'm looking for someone to put this into explanatory terms for me please.

Eg. 4/5 of 20.
In my day, I was told to divide by the bottom and multiply by the top.
He says this doesn't make sense to him but he obviously wasn't listening enough to catch the alternative method!

They changed the way they do sums since I learned, I've no idea how they get to the answer now. Weirdly my brother in law does division the way its taught now and he's older than me!

You're going to have to learn the new way if you want to help, though it makes no sense to me and I'm generally good with maths.

fleet

Purple Mountain wrote: »

Eg. 4/5 of 20.
In my day, I was told to divide by the bottom and multiply by the top.
He says this doesn't make sense to him but he obviously wasn't listening enough to catch the alternative method!

I never liked just being given a rule, applying it and out pops an answer. I had trouble remembering all the rules, much easier to get a grip on what's actually going on even if it took a bit longer.

Perhaps telling him 4/5ths of something just means that for every 5 you get to keep 4.

Then demonstrating with matches or coins.

For your 4/5 of 20 example, I'd change to 3/5 of 20 as that will avoid some initial confusion (4 being both the number of times 5 divides in, and the top half of the fraction).

Purple Mountain

Lisha wrote: »

Lego blocks, pizza/cake drawings are what I use to try and demonstrate fractions.

You have to break it down into something the can feel/touch .

Another one is draw like a thermometer, full being a unit or 100%.

So if I had 1/5, colour it in, and increase the colours to get to 4/5 etc .

I had to use a lot of cutlery to explain long division to my poor brother. He got it eventually. A few years later he realised he very dyslexic with dyspraxia.

I actually had to do long division this week myself as part of an aptitude for something work related and failed miserably.
Does anybody know of any publications to help parents with primary maths?
Even the way he seems to carry over numbers in addition looks different to my method.
Thanks for all your replies.

byhookorbycrook

Purple Mountain wrote: »

I actually had to do long division this week myself as part of an aptitude for something work related and failed miserably.
Does anybody know of any publications to help parents with primary maths?
Even the way he seems to carry over numbers in addition looks different to my method.
Thanks for all your replies.

Have a look at the tip sheets here:
http://www.ncca.ie/en/Curriculum_and_Assessment/Parents/Primary/Tip_Sheets_for_Parents/

And even this is meant for teachers , it will help you with fractions the " new " way.
http://www.pdst.ie/sites/default/files/Fractions Teacher Manual.pdf

kandr10

byhookorbycrook wrote: »

Have a look at the tip sheets here:
http://www.ncca.ie/en/Curriculum_and_Assessment/Parents/Primary/Tip_Sheets_for_Parents/

And even this is meant for teachers , it will help you with fractions the " new " way.
http://www.pdst.ie/sites/default/files/Fractions%20Teacher%20Manual.pdf

Those pdst handbooks are the business!