PEMDAS

Sorry Jack, but you’re wrong there mate.

6 / 2(1+2) = 9 not 1

In mathematics notation a multiplication sign can be omitted. So axb = ab. 2(1+2) = 2 x (1+2), not (2 x (1+2)).

So correctly expanded, the above is:

6 / 2 * (1 + 2) = 6 / 2 * 3 = 9

If it was a function, then you would be correct. But the notation for a function is f(x).

last edited by silentC

Well I’m terribly sorry Jack, but Silent is correct. The rules for this are BODMAS.
B brackets
O of
D division
M multiplication
A addition
S subtraction
so 6/2(1+2) = B 6/2(3) = D 3(3) = M 9 exactly as above.

last edited by Termite

Am I missing a part of a conversation?

Argument on Facebook. I don’t get involved in public debates on the Internet as a rule. I just wanted to let Jack know that the woman he is arguing with is actually right!

And that’s why careless people (like me and Jack) don’t do maths!

But if it were written with a “divide sign” rather than a slash, it becomes completely obvious, as it does if the six is written “over” the two - I guess it’s down to what is familiar graphically! :smile:

6÷2 x (1+2) = 9 is clearer for me!

Mind you, so is 6/2 (1+2) = 9

So I guess it comes down to punctuation in the end.

The confusion arises when people don’t do the functions in the correct order, they end up with wildly wrong answers.

In this particular case, people are thinking that the 2(…) is significant, when it is just shorthand for 2 x (…).

Don’t worry, it looks like the majority of people agree with Jack, so it will probably become mathematical law soon anyway. #fakemaths

administrators

@bitingmidge said in PEMDAS:

But if it were written with a “divide sign” rather than a slash, it becomes completely obvious, as it does if the six is written “over” the two - I guess it’s down to what is familiar graphically! :smile:

6÷2 x (1+2) = 9 is clearer for me!

Mind you, so is 6/2 (1+2) = 9

Sorry, us computerists use the forward slash / for divide instead of the ÷ symbol for the simple reason that back in the day of typewriters, the divide symbol wasn’t one of the keys available. The first computer keyboards that allowed for the punching of punch cards, inherited the layout from typewriters. Programming languages need to be able to express mathematical equations with the characters available, so the slash was it.

0_1500544305651_keyboard.jpg

This is about the laws of mathematics right? Perhaps there’s some confusion around whether or not they apply in this jurisdiction…

Mick

See? The prime minister makes an ill-advised remark and all hell breaks loose!

I remember this ‘law’, we called it Bods Law.

@dog said in PEMDAS:

symbol for the simple reason that back in the day of typewriters, the divide symbol wasn’t one of the keys available.

… but it was easy to type the divide symbol by typing a colon, then backspacing and typing a dash over it.

administrators

Try that on a punched card…

I never did get the punched card thing. Possibly the worst lecturer/subject we ever had… it’s the sort of thing that I could possibly get into if it was half interesting, but instead we had to produce a gant chart and were given the exact data that had to be submitted to the car punching shop… cards punched accordingly, chart printed, nothing learned, less understood, subject passed.

Sounds like my sociology units, less you comprehended or understood the higher the mark, I got a distinction which to this day remains a mystery.
The only punched cards I ever saw were on time clocks, no idea how accurate they were as the employee had to push a lever to punch the card, wonder what happened if it wasn’t aligned quite right or not punched hard enough.

last edited by bunyip

Learned about Punch Card but never worked on them, also learned about Paper Tape & did a Computer Module at RADS on a Mini that had to be programed with Paper Tape.
Never ever had to fix either.

The first data I punched in, and later the first programs, were done on a Halt textolerith punch.
I blame it for the arthritis in my fingers.

administrators

I used punched cards in one semester of COBOL. Never in anger.

Didn’t get along with punched cards or COBOL.

COBOL was my first job, but punch cards were a thing of the past.

I wonder if Jack has realised he is wrong yet?

Jack is probably in PNG hiding. Has he started work yet?

Looks like your connection to The Blokey Shed was lost, please wait while we try to reconnect.