News for hackers. Stuff that matters.

A comment on Nix the Tricks: Math tricks defeat understanding. Parent comment

Re:Nix the Tricks: Math tricks defeat understanding by tome on Sunday September 27, 2015 @08:12AM (#10286263)
> I remember him saying: "Forget all rules about percentages. All you need to know it's like a number multiplied by 100."

I don't remember what rules or tricks I was taught about percentages, but I do remember realising that "%" meant "/ 100" and from there everything else followed.

[ Parent | on HN ]
Re:Nix the Tricks: Math tricks defeat understanding by SixSigma on Sunday September 27, 2015 @09:54AM (#10286485)
But it doesn't mean / 100, it means "per 100"

as described here in "The history of the percent sign"

http://www.shadycharacters.co.uk/2015/03/percent-sign/

[ Parent | on HN ]
Re:Nix the Tricks: Math tricks defeat understanding by plonh on Sunday September 27, 2015 @11:42AM (#10286868)
/ means "per"
[ Parent | on HN ]
Re:Nix the Tricks: Math tricks defeat understanding by Retra on Sunday September 27, 2015 @07:51PM (#10288329)
and × means "of"
[ Parent | on HN ]
Re:Nix the Tricks: Math tricks defeat understanding by asgard1024 on Sunday September 27, 2015 @08:39AM (#10286315)
I went to elementary school in Czechoslovakia, late 80s, and we learned some rules about percentages (which I believe was just a modified formula with the multiplication by 100) as a part of what you call cross-multiplication.
[ Parent | on HN ]