What's the best approach for this question...

littlemissfavored · Post by **littlemissfavored** » Mon Mar 08, 2010 2:04 am

This question is from Bond 4th paper in Maths...

Share 39 sweets among Penny, Ragini & Prue giving Penny 3 times as much as Ragini, and Ragini 3 times as much as Prue.

Penny has --- Sweets, Ragini has --- Sweets, and Prue has --- Sweets.

I did it using algebra my DS 'kinda' got it.
I was wondering am I going too far? Is there an easier way please?

I have seena few questions that I can only solve writing as equations/ algebra...

My DS is taking Bexley and Kent 11+

First-timer · Post by **First-timer** » Mon Mar 08, 2010 2:48 am

You can do this as a ratio question. Ratio is 9:3:1 (work this out backwards from the info given, ie Prue is 1 and Ragini is 3 times this and Penny is 3 times this again). Added together, this gives 13. Divide the number of sweets by 13 - this gives you 3. Multiply the 9:3:1 by 3 to get the answer - 27:9:3.

dadofkent · Post by **dadofkent** » Mon Mar 08, 2010 12:36 pm

In my opinion, no best way. Depends on the child. I founfd initially that the best way was to get DD to work out how many "parts" each child would get. 1 child has one part; 1 child has 3 parts; and 1 child has 9 parts. Total 13 parts. Therefore each part is 3 etc.

I then introduced the other ways to do it, as fractions, as ratios, and as algebra, so DD could see how all the methodologies were essentially the same. Nice easy way to introduce algebra, substituting "x" for "parts", i.e x+3x+9x=39; 13x=39: x=39/13.

Once she got the hang of the different methodlogies, if we were doing timed papers I would let here choose her method, and then when we went thru' answers later, I would also ask her to work out the answer using the other methodologies.

yoyo123 · Post by **yoyo123** » Mon Mar 08, 2010 12:41 pm

that's an excellent approach dadofkent.

When I teach classes and I put a problem on the board I always ask how the pupil got to the answer, then if anyone did it a different way. As you say it makes them realise that there is not always a "right" way to get the answer and they learn to see a problem differently.

littlemissfavored · Post by **littlemissfavored** » Mon Mar 08, 2010 8:07 pm

Thanks to you all-thats great!

Ratios never crossed my mind and I have only just started teaching DS ratios.

I appreciate it all the responses.

mattsurf · Post by **mattsurf** » Mon Mar 08, 2010 9:46 pm

We used the algebra method... probably because I didn't think about ratios. However, algebra is very likely to come up so using this type of question to get DC thinking in this way is really useful too

By the way, ratios will also come up