A math question for Singaporean kids aged 11 has gone viral. Otherwise known as Cheryl’s Birthday Problem, this is actually something not many people pointed out, and I just realised.

Maths is not all about numbers. Logic is part of maths, too.

Consider the problem, in full as the header image shown, can you guess the answer?

No? It’s okay, there’s a professional mathematician who can explain the solution.

So, are your answers lined up with the solution? Maybe consider this, there’s also another solution that may seem true as well, depending on who you ask.

Personally, I don’t like number operations. I sucked at Additional Maths back in secondary school- only managed to get pass the paper until the SPM trials *(Sijil Pelajaran Malaysia, equivalent to the British O-Levels)*. It’s the only reason why I couldn’t enroll for an engineering course (thank God), despite being in one of the top engineering universities in the country, or so they claimed. It’s the only subject that brought me down form being a straight-A student at the time.

Instead, I took IT.

During the classes, I realised many people were struggling with programming classes, I started to wonder, why?

It turns out programming requires a different set of skill than that what we usually been trained of. **Logical thinking.**

Sure, if anyone can cram enough to memorise all the formulas, they could solve the problem, but what if the problem does not require you to just plug the numbers into a certain equation, like Cheryl’s Birthday Problem?

Logical thinking goes beyond the procedure-based problem solving. You have to figure out the rules the situation has, and what would happened if you manipulate any variable- any number that is associated with it.

And with that, it makes a bit of sense there’s a discipline called Computer Science that requires good maths instead of science as a pre-requisite, despite having science in its name.

*(Do note that IT and Computer Science are two completely different disciplines. IT is more broad, covering wide range of topics, like databases and networking, whilist CS covers more on the programming side, optimising algorithms, and more in-depth topics I know nothing of.)*

I also wondered why hasn’t my lessons in maths cover this part of math more? Why just focus on the complex use of numbers, where is the logical thinking part?

Turns out, there were, I just didn’t noticed.

There’s actually another math subject, where Additional Maths are only taken for certain students taking science stream, there’s a vanilla, or basic math subject that every Malaysian secondary level student takes, dubbed Modern Maths. Let me tell you, it’s easy.

Part of Modern Maths being deemed an easy subject is the part of logical thinking. It was really easy to grasp, back in the school days, again, all of classmates, even from lower classes can master it. Maybe it was really easy we just memorised the whole thing instead of going through the thought process. Maybe because we had an excellent Maths teacher (shout-out to Sir Azlan) that had guided us really well.

And then I remembered me enjoyed when our Add Maths teacher explained the complicated step on how we derived the important formulas. Of course, everyone is bewildered, or asleep, from the explanation, yet I enjoyed how the origin story unfolded, despite not able to comprehend it at the time. There’s a thought process, a logical explanation on how it all appears to be.

And that explained how I was able to learn solving the Rubik’s Cube. It’s not just random shuffles that can make it all magically appear in perfect order, or removing the stickers. There’s a logical algorithm that can move specific pieces without disrupting the others.

All this accumulates to a conclusion, I didn’t hate maths, what I hate was large number operations. Yet I adore logical and programming problems. Glad that I did took IT, I kinda have the natural talent for it.

Alhamdulillah.

(P.S: The answer is July 16)