SIA IS GOOD ON MATHS OR SIA IS GOOD AT MATHS?
Using at and on.
Here are two(2) sentences
1.Sia is good at maths (grammatically correct)
2.Sia is good in maths
(grammatical wrong)
Sia is good at maths ( here "at" is used because maths is not like a room.)
Sia is good in maths ( in this sentence, "in" is used because maths is referred as a structure that has boundary or look like a house. Therefore, Sia good in math is grammatical wrong.
Do you accept or not?