Ratios
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Ratios
Does anyone know any good websites or books to explain ratios? Daughter in Yr 5 due to take Kent test in Sept and often struggles with these sort of questions.
Why not go to a big Waterstones or WH Smiths and look through the KS2 maths books with her, and get her to choose one she likes the look of, with particular reference to the ratio section. Also, see if she has covered it at school already, and look at whatever teaching methods they used then.
Also, follow the links in some the other maths threads and you will find some good websites for KS 2 stuff
Good luck
Also, follow the links in some the other maths threads and you will find some good websites for KS 2 stuff
Good luck
I would also share out sweets (or similar) is n the ratio 2:3 ie I give Mary 2 sweets for every 3 sweets I give John - then compare amounts after each 'sharing'.
2:3 = 4:6 = 6:9 are all equivalent ratios
Then look at 2:3 is the same as sharing something into 2/5 and 3/5 - this is quite a big jump.
Make up squash - 1:4 is common but you may be able to find others in the shop. If I pour out 10 ml of concentrated squash how much water do I need to add? later move on to - if I've made up 200ml of diluted squash how much water did I use?
2:3 = 4:6 = 6:9 are all equivalent ratios
Then look at 2:3 is the same as sharing something into 2/5 and 3/5 - this is quite a big jump.
Make up squash - 1:4 is common but you may be able to find others in the shop. If I pour out 10 ml of concentrated squash how much water do I need to add? later move on to - if I've made up 200ml of diluted squash how much water did I use?
Hi Kentish Maid
I agree that it is necessary to show a students the foundations of ratio. However, under test conditions they need a good mathematical method & technique.
For working out the distribution of an amount the student quite simply needs to work out the "value of one unit".
The simplest ratio is the 2:1 ratio.
There are 2 + 1 = 3 units
So if a value of say 24 needs to be distributed 2:1
Divide 24 by 3 = 8
Therefore 2 units is 2 x 8 = 16
and 1 unit is 1 x 8 = 8
The student can check the answer 16 + 8 = 24
24 is a good value to use as you can apply
2:1, 3:1, 5:1, 7:1 and 11:1 ratios as well as the 3:2:1 ratio
When looking for books, look at those that contain a good explanation and example with some exercises, always evaluate whether the student understands and completes exercise correctly, then extend to more complex questions.
Regards
Mike
I agree that it is necessary to show a students the foundations of ratio. However, under test conditions they need a good mathematical method & technique.
For working out the distribution of an amount the student quite simply needs to work out the "value of one unit".
The simplest ratio is the 2:1 ratio.
There are 2 + 1 = 3 units
So if a value of say 24 needs to be distributed 2:1
Divide 24 by 3 = 8
Therefore 2 units is 2 x 8 = 16
and 1 unit is 1 x 8 = 8
The student can check the answer 16 + 8 = 24
24 is a good value to use as you can apply
2:1, 3:1, 5:1, 7:1 and 11:1 ratios as well as the 3:2:1 ratio
When looking for books, look at those that contain a good explanation and example with some exercises, always evaluate whether the student understands and completes exercise correctly, then extend to more complex questions.
Regards
Mike
Mike Edwards is a co-author of The Tutors product range.