Maths Fail or Act Young?

I told my mum we booked buffet for dad's bday.
She replied saying oh book buffet invite people ar for your father's 50th bday ar?
2 big mistakes.
1) Book at a restaurant la. Can invite how many ppl for a "50th bday" when we aren't any big shots. HAHA!
2) My dad where got only 50 yrs old! OMG!

Then I say what 50, already 52 rite (she made me suspect myself cos usually she is right with their ages).
Then she say 50 ma.
I say now 2010 le leh, you substract 10 with 8(cos dad born in 1958, i tink) you get 2 ma where got 0.
Then she open her eyes and say means she 53.
Still asked me she got 53 meh.
WAH I looked at her and think to myself u act young or u maths fail.
I believe is the latter cos her maths v lousy.
Result of don't want to study after Primary School.
HAHA!
But my dad's maths power leh.
Haha.