Situation:

A Primary School Leaving Examination (PSLE) math question involving 2 individuals (“Helen” & “Ivan”) and their unknown number of coins was starting to trend on social media and made rounds on msging apps.

It was a busy evening, so I did not think much of it until the next morning (Saturday). I then recalled that our bank had a coin deposit service that was free-of-charge, based on some community management responses I had seen. I began sending some queries to a few colleagues whom I knew would have the answers.

Brief:

Could we ride on this trending topic to talk about an (unsexy) service like coin depositing?

Objectives:

To create awareness of this free coin-deposit service and engagement around this examination frenzy.

The original PSLE examination question:

Helen and Ivan had the same number of coins. Helen had a number of 50-cent coins, and 64 20-cent coins. These coins had a mass of 1.134kg. Ivan had a number of 50-cent coins and 104 20-cent coins.

(a) Who has more money in coins and by how much?

(b) given that each 50-cent coin is 2.7g more heavier than a 20-cent coin, what is the mass of Ivan's coins in kilograms?

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The first half was the perfect segue to our OCBC New ATMs where customers could bank in coins for free, of course telling you exactly what you deposited.

The challenge was presenting this concisely, so all the math in the world would seem unnecessary in this context. Hence - "They brought their coins to an OCBC New ATM and banked them in for free." To bring it home, "The End." was added.

Data gathering:

Anecdotal evidence (based on my WhatsApp notifications and Facebook feed) showed increasing buzz around the solution needed to score full marks.

Target audience:

The audience was initially parents of 12-year-old children who took this national examination, but the post grew in popularity amongst all Singaporeans who were possibly stumped by the question's difficulty and tickled by the simplicity of our solution.

Relevance:

As interest around the exam question gained momentum on Facebook, it was natural that we looked at Facebook to ride on the interest. We also wanted to keep the execution simple.

Approach:

It was the weekend, so I didn't want to trouble anyone to get their work laptops. Also, I wanted to challenge myself to demonstrate the power of a simple idea being more effective than other projects where we worked with a lot more resources. Hence, this text-only post was produced entirely off WhatsApp.

I looked for the exact wording of this exam question to see if our coin deposit service would in fact have solved this math question. I drafted the post and circulated it amongst my colleagues to check for accuracy and their reactions, then to the Head of department for clearance.

Timeline:

Friday (1 Oct 2021)

1030am-1200pm - PSLE Mathematics Paper 2 conducted at schools around Singapore

Evening - Qn 15 from PSLE Mathematics Paper 2 featuring Helen & Ivan and their unknown number of coins begins circulating on social media and messaging apps

Saturday (2 Oct 2021)

12.05pm - 1st (and only) draft sent

12.19pm - Approval received with no changes

12.27pm - Post published on Facebook with no boost

Summary:

10 minute production time, 14 minute approval process

Reach: 241k

Engagement: 31k

Shares: 1.4k

Sales: N/A