Thursday, February 20, 2014

How I suck at primary school math

A good friend of mine asked me to solve this primary 5 math problem for her. It goes like this:

At a charity walk, 150 participants were adults. 1/3 of the children were boys. If 1/4 of the participants were girls, how many people were at the charity walk?

Can I do it? Of course, but I've to use algebra. I managed to get it in the first try, maybe in less than 3 mins? But you and I know that primary school maths do not involve a lot of algebra, if at all. And the way to solve such problems is to use the 'model' method and I know how I suck at this method of doing math. I tried for a good 30 minutes before giving up, attempting another question, hit an inspiration and went back to do it for another 15 minutes before I finally got the answers using this weird blocks of rectangle that is so typical of the model method.

Am I bad in math because I couldn't solve the problem using the prescribed method? Obviously not, because I can solve it so much faster using another method of doing it. Similarly, for someone who is so good at using the model method, does it mean that he is good in maths? I've seen many students who had very good scores in primary school maths (obviously they must know a great deal about the model method) but failing miserably when the model is no longer used in secondary school. Does it mean that they are no longer good in maths?

On reflecting, a few thoughts came to mind:

1. Don't be judgemental. Perhaps a person's potential is not shown because the the right method to bring out his best is not there yet. Also don't be judgemental on your own abilities. Just because you can't do it now doesn't mean that you are bad in it. Perhaps you haven't found the way that best suits you.

2. Don't be too proud of your success. Perhaps you just happened to hit on something that just comes naturally to you. When the full extent of the problem is shown to you in the future, you might not be able to transfer whatever worked for you in the past to the future. At best, it's just domain-specific success; once you're out of that specific domain, you're not longer that good.

3. Be open minded and try out new ways to do things. Don't be stuck in ways that worked for you in the past.

We tend to diss things that we're not good at, and praise the system that had been working so good for us. In this case, I can always complain why can't primary school use algebra to solve math problem - it'll be so much simpler (for me). Or I can start teaching primary school kids algebra, because that's the way to solve such problems (for me).

Or if I'm superb at the model method and is very good at primary school math, when I enter secondary school and I suck at algebra, I'll start using modelling model and diss the teacher for teaching me algebra. Why learn something so complicated (for me) when I can draw models and get the answer anyway?

Ultimately, I think that whoever is good in maths isn't necessary someone who is good in maths right now at this moment or worse, in the past. He is someone who exhibits the ability to be good in maths in the future. In the future, there's so many problems and challenges that are thrown at you from all sorts of angles that you have no way to succeed without being non-judgemental (so that you don't give up when you encounter new things), humble (so that great teachers can appear and can teach you) and being open-minded (so that you can use new ways to solve old problems).

That, is why you learn maths. That, is what you tell students when they ask you why they need to learn how to integrate and solve trigonometry problems when in real life they don't even use it. That, is the reason for learning anything at all, really. Because when the subject matter has long been forgotten, the way you approach life's multitudes of problems and the way you tackle them will always be the same as the way you handle your humble maths problems.

(For those who tried the question and wants to know the answer, it's 240. At least that's what I got.)


Derek said...

Hi LP,

I'm worse. 150 participants are adults. 1/4 of those 150 participants were girls. 150/4 is not a round number. I'm stuck. LoL.

la papillion said...

Hi Derek,

I think by 'girls', they refer to children who are female. So out of the total participants, some are children, 150 of them are adults. Out of the children, 1/3 are boys and the rest are girls. Now, it also happens that the girls make up 1/4 of the total participants.

Try again? :)

Derek said...

Makes more sense now. I took 30 mins with algebra. If I use models, I will have to burn midnight oil le. LoL.

la papillion said...

Hi Derek,

Wah, LOL! Not easy right, primary school maths!

Singapore Man of Leisure said...

I feel like crying...

Totally lost.

No idea what is modelling model. Don't recall learning it at secondary school. I never took A. Math.

Algebra? I though algebra got a, b, c?

Where's the a, b, c in the question???

I now go to the bathroom mirror to regain my self-worth.

Dang! I still handsome :)

Airhead SMOL?

Anonymous said...

Hi LP,

Yeah. "Don't judge a fish by its ability to climb trees and proclaim it's an idiot"


la papillion said...

Hi Aceirus,

Indeed. But it's easier said than done. I've done my own fair share of being judgemental too. But I really really try not to do it, especially after last year. Some personal experience reinforce that strongly.

I only hope that in the face of anger, I can still rmb not to judge prematurely.

la papillion said...


Don't worry, a lot of adults can't do it as well :) Still life goes on, isn't it? It always does :)

B said...


Oh gosh... like smol im worried now. This seems like a very easy questions but it seems our brain stopped since we can only do additions and subtraction now.

Anonymous said...

Stupid question, that's why so many youngsters nowadays so ku-ku brain...

answer is 240.
total = adult + children
girls = 1/4 total
boys = 1/3 children
girls = 1-1/3 = 2/3 children
2/3 children = 1/4 total
children = 3/8 total
total = 150 + 3/8 total
5/8 total = 150
total = 240

la papillion said...

Hi B,

Well, it's not easy. I realised a good number of primary school questions are not defined clearly. It seems that there's some room for misinterpretation because of the unclear phrasing. Or maybe it's just a matter of thinking too much.

But it's definitely stressful for both parents and their kids, esp at pri 5 when suddenly a lot of things become harder.

la papillion said...

Hi anonymous,

Not knowing how to do this doesn't mean they are stupid. Knowing how to do this doesn't mean they are clever.

Thanks for being the example to illustrate the intention of this blog post.

Singapore Man of Leisure said...


You're beautiful!

Straight talker you :)

EY said...

Hi LP,

I learnt enough Mathematics in kindergarten to survive the adult world. :P

I'm one of those who couldn't make sense of algebra nor do I see much relevance in all those geometry that we did. Maths was a torture. Haha.

And to think that I was once upon a time one of those 'culprits' to set questions like this? Yikes! LOL~

You are good! 3 minutes. Got speed got accuracy. :D

la papillion said...

Hi EY,

Ah, you flatter...everyone has their own talents, even if we have to take a while to discover them :)

It's only sad that instead of measuring what is important to us, we treat what we is measurable as important. In this case, whatever math result is deemed more important that the soft skills needed to do the subject, simply because a test result is immediately measurable.

Ah...the illusion of certainty in numbers.

Anonymous said...

Nope. Model and elimination method by algebra are essentially the same thing.

Once the kid gets that (and lowest common multiple), the maths get easy.


la papillion said...

Hi jwt,

What did you say "Nope" to?

Essentially the same thing? Well, I agreed theoretically the same thing, but practically different. It's still not easy for me to do model method...does it mean I don't understand lowest common multiple and that I don't know that model and elimination are the same thing? Perhaps lol