Maths Question

Ha just realised it auto corrected should say Bidmas

 

I've had difficulties with number 10 for years...

 

Try this one then hee hee: -

1 + 2 × 3 ÷ 4 - 5 = ?

 

-2.5

 

Absolutely bang on!

 

Arrgghhh!!! Confused.

Brackets then orders BEFORE Division and Multiplication.... What do you mean by 'Orders' in BODMAS ??

If O overrides D and M then it would mean 5+1 then the sum multiplied by 10 = 60

However I know you are correct so I am not arguing.

A simple check on the calculator or spreadsheet without parentheses i.e. =5+1*10 returns 15 but has always used parentheses in formulas etc so either have forgotten BODMAS or was never taught it (did O level maths and HNC engineering maths neither of which mention it.) BTW pretty crap at both but a wizz with financial spreadsheets being a tight git.

 

Are we talking precedence here?

 

"Orders" means raising a number to a power, that is, squaring, cubing, taking the square root etc.

http://www.skillsyouneed.com/num/bodmas.html

 

Yep, operator precedence.

The original question was 5 + 1 × 10 = ?. This is common on Farcebook and most people get it wrong, the most common answer is 60. Some people claim it's ambiguous, but it's not, it's clear once you know the rules.

One bloke on Farcebook got 24.5 hee hee!

 

Well my calculator answer is 60 which was the answer I got by mental arithmetic. I was taught at grammar school (late fifties to early sixties) and we were taught to work from left to right unless there were brackets. Never taught owt different when doing my HNC in Engineering, well not that I recall. Mindst you if someone tells me that Donald Duck is a squirrel I will know I have lost it.

 

That's because you don't do it in the order it's written, you do the multiplication first. So it's 1 x 10 = 10, then add 5 making 15.

Here's another one: -

6 - 1 x 0 + 2 ÷ 2 = ?

 

7.

Whilst we're on maths questions, here's one for you - a disease is discovered that randomly affects 1 in 10,000 people irrespective of age, gender or race. It is symptomless until you suddenly drop down dead, however there is a 99% accurate test to determine whether you have the disease. You go to the doctors, have the test, and it comes back positive. What is the probability that you have the disease?

 

Absolutely bang on, again!

I've seen the disease problem before so I won't spoil it.

 

Thats what we were taught too, if somebody asked you that question verbally the answer would always be 60.

 

Not saying your wrong, just stating I did it the way I was taught (which now it seems is deemed incorrect). We were also taught that an atom is the smallest indivisible part of an element. How wrong they were. However, back to the maths. You had to apply brackets in my day to suggest order of preference. No brackets then calculate left to right. Seems to me its to accommodate the idle barstewards who won't apply brackets or to allow students to use calculators in exams where the use of brackets wouldn't work.

 

99%

 

Those are easy.

Try this...

If Wayne goes to the bar with £20 and comes back with five pints and £7 in change how many pints has Wayne brought?

 

I have to say I learnt it the BODMAS way at Holgate in the 70s.

 

Zero?

 

Nope, it's actually just under 1%!