Two weeks ago, I made a small but meaningful mistake on LinkedIn.

In my post about the Hire-Purchase (Amendment) Bill 2025, I mentioned the “Rule of 72” thinking it referred to the interest calculation method under hire purchase loans.

Todayr, one of my followers, Mr. Mark Chan , gently pointed out in the comments:

“I think you mean the Rule of 78, not Rule of 72.”

That single line reminded me why I love sharing on LinkedIn.

In our line of work, accuracy matters.
But what matters even more is humility to learn.

LinkedIn has given me not just visibility but a community of professionals who care enough to correct me.

I’m grateful to Mr. Mark Chan for his kindness and generosity in sharing knowledge publicly.

For the record. Mr. Chan was absolutely right.

Rule of 72 is a formula used in investment and finance to estimate how long it takes for money to double, given a fixed annual rate of return.

Rule of 78, on the other hand, is used in hire purchase to allocate interest across the loan term.

It’s a method that front-loads interest meaning borrowers pay more interest earlier in the repayment schedule.

The upcoming Hire-Purchase (Amendment) Bill 2025 plans to remove this Rule of 78, making loan interest fairer and more transparent for consumers.

So yes! My post should have read “Bye Bye Rule of 78,” not 72.

There’s a reminder that no one knows everything, not even an auditor and tax agent. Thank you, Mark.

And thank you to everyone who continues to read, comment, and teach me along the way. #闻过则喜

PS : Authored by Mr Koh Teck Peng, the group principal of KTP, in his personal LinkedIn post.