My DD briefly told me she couldn’t complete this question in PSLE. She was using algebra (again) and trying to figure out “the formula”. I didn’t have time to dwell on this until Science paper today. Someone sent me one online solution for this questions yesterday and I took a look and trust in my heart that MOE will not set such “killer” question so I try to stand outside the box, and find a simpler way. And I found it below, I think.

(Part A is FOC marks, to encourage kids to do attempt to complete this table to see the pattern for Part B) *Though I’m not sure if the table has a row for “Total no. of triangles”, which is very important here.*

(Part B is to deduce formula of perfect square) 250 x 250 = **62,500#**

(Part C solution: If we cancel out the white and grey, the remainder is the figure nth number (odd white or even grey) **So in 250th figure, there are extra 250 grey triangles**.

So no. of white triangles = (62500-250)/2 = 31,125

So % of grey triangles = (31,125 + 250)/62500 = **50.2%#**

I think what could be the simple way of thinking of the setter may not be so simple for kids of P6, especially those of MO, GEP, formula-taught kids. And understandably, this is a misalignment that cause some parents or students to be upset. Hope we all can see the beauty of simplicity and enjoy Maths or enjoy teaching Maths in a simpler way.