Re: Maths, who is the thicky ? Not me I hope !

[Just Katie]

 Well, according to my daughter

Part 1 green is correct and should read 40-(12/6)+4=42

Part 2 green is obviously 150

blue is 170 as it reads.

[Alex H]

So Brackets first 12 divided by 6 = 2

OK so far

Next the addition so 2 + 4 = 6

Nope - its -2 + 4 = +2

Then the subtraction

So 40 - 6 = 32 No again [:(]

So 40 + 2 = 42

[Pierre ZFP]

'D' is definitely the answer to Life, The Universe and Everything (42)

The precident of doing the brackets and '*'  '/' operators first is even given in questions A B and C !

Of course you get a very different answer if you just use a calculator and perform the operations left to right, doesn't make it correct though.

 

[Just Katie]

No, I always did brackets first.

40-(12/6)+4=42

40-2+4=42

Edit you beat me to it!

[Joy1]

Hi puzzled. Do you have a child in 5eme? My son has just had a similar exercise for his home work. I am useless at maths (forgotten everything I learnt anyway!!!) - thankfully husband can remember how to do these! Joy

[Punch]

BODMAS is the usual order;

Brackets of Division, Multiplication, Addition , Subtract

 

[Hagar]

[quote user="Punch"]

BODMAS is the usual order;

Brackets of Division, Multiplication, Addition , Subtract

 

[/quote]

Sorry Punch - disagree with that - I was always taught and have always worked with brackets first then from left to right regardless of the operation i.e in the example

(12/6) =2

40-2=38

38+4=42  QED

This doesn't work if you are Polish.

rgds

Hagar

Edited - And before anyone else points it out I know that would give an answer of 540 to example C above - but then I would maintain that is the correct answer.

 

 

 

 

[Hagar]

Oh - and another thing (just to prove I can be a real pedant) - this is Arithmetic not Maths.

rgds

 

Hagar

[Punch]

You can diasgree Hagar but I think you'll find that BODMAS is the tried a tested (and correct) method !

Do a simple search on google for BODMAS ( In fact the O stands for Order not Of as I said above)

Take a look at these links;

http://www.mathsisfun.com/operation-order-bodmas.html

http://www.easymaths.com/What_on_earth_is_Bodmas.htm

http://en.wikipedia.org/wiki/Order_of_operations

And here's some for you to try your method out on  and see if you get the right answers !

http://www.abacustraining.biz/bodmasExercises.htm

 

[Hagar]

Thanks Punch - I Know - I know - looked it up myself. BUT - I have an O level in Arithmetic don't you know[:P] - special peculiarity of a Scottish socialist state comprehensive education.

Funny how I managed to work in technolgy for best part of forty years and never made that mistake before. (Or maybe that's why that ship fell over in Antwerp - I used to design stabilisers)[:D]

Anyway - on a  more serious note (only slightly) I think the example is badly presented - for clarity exra parentheses should be used.  

rgds

Hagar

[Hagar]

Punch - Just to add a little -

 this from a professor of mathematics (my italics).

"Ambiguously written fractions. In certain common situations with fractions, there is a lack of consensus about what order to perform operations in. For instance, does "3/5x" mean "(3/5)x" or "3/(5x)" ?

For this confusion, teachers must share the blame. They certainly mean well -- most math teachers believe that they are following the conventional order of operations. They are not aware that several conventions are widely used, and no one of them is universally accepted. Students may learn one method from one teacher and then go on to another teacher who expects students to follow a different method. Both teacher and student may be unaware of the source of the problem.

Here are some of the most widely used interpretations:

• The "BODMAS interpretation" (bracketed operations, division, multiplication, addition, subtraction): Perform division before multiplication. For instance, the function f(x) = 3/5x gets interpreted as (3/5)x = . In particular, f(5) = 3 and f(1/5) = 3/25.

• The "My Dear Aunt Sally" interpretation (multiplication, division, addition, subtraction): Perform multiplication before division. For instance, the function f(x) = 3/5x gets interpreted as 3/(5x) = . In particular, f(5) = 3/25 and f(1/5) = 3. Likewise, "ax/by" would be interpreted as "(ax)/(by)".

• The interpretation used by FORTRAN and some other computer languages (as well as some humans): Multiplication and division are given equal priority; a string of such operations is processed from left to right. For instance, "ax/by" would be interpreted as "((ax)/b))y", or more simply "(axy)/b". "

Guess I must be a FORTRAN Human.

rgds

Hagar

[Joy1]

Dont you just love maths homework![8-)] I have to leave all the maths stuff to my husband! I used to be the expert on all things biological , geographical and historical- until we moved to France that is! Unfortunately my french is no where near good enough yet! Once my son has translated it into english for me, I have a go at helping! Its not much fun knowing less than the kids! Joy

[Punch]

[quote user="Hagar"]

Punch - Just to add a little -

 this from a professor of mathematics (my italics).

"Ambiguously written fractions. In certain common situations with fractions, there is a lack of consensus about what order to perform operations in. For instance, does "3/5x" mean "(3/5)x" or "3/(5x)" ?

For this confusion, teachers must share the blame. They certainly mean well -- most math teachers believe that they are following the conventional order of operations. They are not aware that several conventions are widely used, and no one of them is universally accepted. Students may learn one method from one teacher and then go on to another teacher who expects students to follow a different method. Both teacher and student may be unaware of the source of the problem.

Here are some of the most widely used interpretations:

• The "BODMAS interpretation" (bracketed operations, division, multiplication, addition, subtraction): Perform division before multiplication. For instance, the function f(x) = 3/5x gets interpreted as (3/5)x = . In particular, f(5) = 3 and f(1/5) = 3/25.

• The "My Dear Aunt Sally" interpretation (multiplication, division, addition, subtraction): Perform multiplication before division. For instance, the function f(x) = 3/5x gets interpreted as 3/(5x) = . In particular, f(5) = 3/25 and f(1/5) = 3. Likewise, "ax/by" would be interpreted as "(ax)/(by)".

• The interpretation used by FORTRAN and some other computer languages (as well as some humans): Multiplication and division are given equal priority; a string of such operations is processed from left to right. For instance, "ax/by" would be interpreted as "((ax)/b))y", or more simply "(axy)/b". "

Guess I must be a FORTRAN Human.

rgds

Hagar

[/quote]

 

Thanks Hagar, I've got a spanking headache now looking at that lot.[8-)]  lol.

 Bodmas was the only thing I remembered from maths at school, but I concede there are so many ways to crack a nut. [:)]

[Bilbo]

The BODMAS thing is not to be taken rigorously as multiplicationand division have equal priority as do addition and subtraction. You also have to remember that the sign goes with the number after it.

My confusion with the original post was becaue there were no brackets shown in the question. Once they were put in everything changed. So were they there or not?

[AnOther]

Call me the total thicky or put it down to being a dinosaur who's completely out of touch with what constitutes maths (or Arithmetic) these days but if I read those sums literally and as I was taught at school I get radically different answers [:-))]

Allow me to dissect it step by step in my nieve neanderthal fashion:

D =  40 - 12 divided by 6 + 4  Answer 34     OR  D = 40 - 12 divided by 6 + 4 Answer 42

40 - 12 = 28      divided by 6 = 4.6666      plus 4      Answer = 8.6666

Even if one puts ( ) around the 6 + 4 it still doesn't work.

40 - 12 = 28      divided by (6 + 4) (or 10)      Answer = 2.8 

I find it hard to believe that the sum has been faithfully reproduced because without brackets it cannot logically be worked to give the answer 42

viz: and as Katies daughter says,   40-(12/6)+4=42    are the kids really taught without brackets !!!!!!!!!!!!!!!

I got bored so haven't even looked at the second sum [:P]

PS: Never ever heard of BODMAS, sounds like a resort in Turkey to me, is it nice there [:$]

[LEO]

Well "summed" up Ernie !

[retread]

This place BODMAS is it anywhere close to the place I remember, BMDAS?

or Be My Dear Aunt Sally

or Brackets, Multiplication, Division, Addition, Subtraction.

As for the sums, there must be a 10yr old out there!

[LEO]

IMHO , Algebra and Arithmetic cannot be rewritten, so you can shove your "BODMAS"

[Missy]

[quote user="ErnieY"]

Call me the total thicky or put it down to being a dinosaur who's completely out of touch with what constitutes maths (or Arithmetic) these days but if I read those sums literally and as I was taught at school I get radically different answers [:-))]

Allow me to dissect it step by step in my nieve neanderthal fashion:

D =  40 - 12 divided by 6 + 4  Answer 34     OR  D = 40 - 12 divided by 6 + 4 Answer 42

40 - 12 = 28      divided by 6 = 4.6666      plus 4      Answer = 8.6666

Even if one puts ( ) around the 6 + 4 it still doesn't work.

40 - 12 = 28      divided by (6 + 4) (or 10)      Answer = 2.8 

I find it hard to believe that the sum has been faithfully reproduced because without brackets it cannot logically be worked to give the answer 42

viz: and as Katies daughter says,   40-(12/6)+4=42    are the kids really taught without brackets !!!!!!!!!!!!!!!

I got bored so haven't even looked at the second sum [:P]

PS: Never ever heard of BODMAS, sounds like a resort in Turkey to me, is it nice there [:$]

[/quote]

 

Ernie ... the fatest milkman in the West! (sorry but my father -French!- loves his Benny Hill and would sing it in the bathroom. The only English he does know!)

Anyway I had the same answers as you.  But then who am I ... me who sat for 2 hours at her BEPC mathématiques (in antiquity time so many moons ago) to only put her number, the date, the title of each question to be answered with enough room for the purpose...... then stared at the clock to get out of that room the fastest possible way I could !!! 

 

as to Bodmas ... on first reading I read Body Mass.. then thought that 's wrong so double take.... Bodmas... thought it was a place in Wales [:D]