My feed
Premium

Please
or
to access all these features

Join our Primary Education forum to discuss starting school and helping your child get the most out of it.

Primary education

Maths question help

10 replies

Gileswithachainsaw · 26/04/2017 20:22

I know the answer however I need to know what method/how to explain how to get the answer appropriate for a yr 5

Tom thinks of a number

He adds half the number to a quarter of the number and makes 60

How would you teach a 10 yr old how to figure it out. As my method is probably no good Grin

OP posts:
Report
PurpleDaisies · 26/04/2017 20:24

If he adds half of the number to a quarter of the number, he's made three quarters of the number.

If the knows what three quarters is, he can work out one quarter, and then the whole number.

Report
Gileswithachainsaw · 26/04/2017 20:26

See i just divided by three then times by four

I was just checking tht there wasn't supposed to be some kinda x+y =z thing that yr 5s start being taught about now and we were missing the point :)

OP posts:
Report
CarrotCakeMuffins · 26/04/2017 20:27

Use Algebra. Where a is Tom's number.
So 1/2 a + 1/4 a = 60
3/4 a = 60
a = 80
Assuming I've understood the question right.
Hope that helps

Report
CarrotCakeMuffins · 26/04/2017 20:28

Dd has done a bit of algebra in yr 6 but not sure about year 5

Report
Gileswithachainsaw · 26/04/2017 20:30

I will check with dd

As marks are also giving for workings I just wanted to check that we hadn't missed something

Thanks Smile

OP posts:
Report
Ginmakesitallok · 26/04/2017 20:30

I'd go with carrot cakes explanation.

Report
senua · 26/04/2017 20:35

I agree with carrot. I think the main thing to teach is:
accept that you don't know the answer yet and that is OK.
we'll invent a thingy to call this unknown ('a' in carrot's workings)
convert the words into Mathematical symbols
don't panic
follow mathematical logic and it all falls into place
simplesSmile

Report
Gileswithachainsaw · 26/04/2017 20:36

Thanks everyone Smile

Seems I was kinda right minus the algebra Grin

OP posts:
Report
PurpleDaisies · 26/04/2017 20:37

I don't think that most year 5s will be able to do that algebraically. They are used to doing problems based around adding fractions and finding a whole number if you know half/a quarter etc.

Report
cantkeepawayforever · 26/04/2017 21:12

A year 5 might be more familiar with this as an 'empty box' problem (these are introduced from really early years, with the box standing for the unknown - so even a Y1 or Y2 child would be familiar with e.g. 3 + [] = 10, the number in the empty box must be 7).

So they might say
half a number plus quarter of a number is three quarters of a number.
So 3/4 of [] (empty box) = 60
One quarter of [] = 60 divided by 3 = 20
If 20 is 1/4 of the number, the whole number must be 20 x 4 = 80

Children might not always work through the steps after the 3/4 of [] = 60 numerically as I have shown. Some might draw a diagram in which they show 3/4 of a whole, label the 3/4 60 and then spot that each 1/4 must be 20 so the whole is 80. others might sport the relationship between 6 and 60, and use their knowledge that 6 is 3/4 of 8 to say that 60 is 3/4 of 80, or embark on some trial and improvement.

Report
Please create an account

To comment on this thread you need to create a Mumsnet account.