Math Is Fun Forum

optrex

Member

Registered: 2008-01-11

Posts: 1

Do we use BODMAS or not?

My 10 year old daugher has the following numeracy questions

13 + 7 / ? = 6
she has answered 5 here

and

7 + 49 / ? = 7
she has answered 8 here

obviously working from left to right those answers are correct. But what happened to BODMAS? Surely the questions should be worked out as

7 divided by something, then add 13 = 6

and

49 divided by something, then add 7 = 7

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Do we use BODMAS or not?

you are correct, the divisions should be done first here, however unfortunately it doesn't seem that that is what they want her to do, they seem to actually want her to do it the wrong way, because working through them properly you get -1 and the second question has no answer because there is no such number that 49/? = 0 unless it is purposefuly meant to be a trick question as you sometimes will get -> i.e. you are meant to answer (there is no answer) and explain why, with the trick being that some students would still atempt to work it out

and also, her first answer if you do work left to right is still incorrect anyways, if you work from left to right ignoring BODMAS
you get 20/x = 6. x =

i would suggest that the correct answers are  -1 and (no answer)

Last edited by luca-deltodesco (2008-01-11 23:29:50)

---

The Beginning Of All Things To End.
The End Of All Things To Come.

optrex

Member

Registered: 2008-01-11

Posts: 1

Re: Do we use BODMAS or not?

many thanks luca

Devantè

Real Member

Registered: 2006-07-14

Posts: 6,400

Re: Do we use BODMAS or not?

Yeah, people tend to forget about BODMAS these days.

Of course, that's not to say that you shouldn't use it. BODMAS is a really key part of arithmetic ...

NullRoot

Member

Registered: 2007-11-19

Posts: 162

Re: Do we use BODMAS or not?

Just like in writing, the only thing more important than putting in the right symbols is putting them in the right place!

A woman without her man is nothing.
A woman. Without her, man is nothing.

---

Trillian: Five to one against and falling. Four to one against and falling… Three to one, two, one. Probability factor of one to one. We have normality. I repeat, we have normality. Anything you still can’t cope with is therefore your own problem.

treehugger96

Member

Registered: 2007-12-24

Posts: 10

Re: Do we use BODMAS or not?

i think they want her to work from left to right. A ten year old would be in grade 5 or 6. You learn BODMAS and decimals in grade 7.

---

........"To my mind having care and concern for others is the highest of human qualities"
.........Fred Hollows

JohnnyReinB

Member

Registered: 2007-10-08

Posts: 453

Re: Do we use BODMAS or not?

I was taught it when I was in grade five.

Different cultures, different curriculum, I guess.

---

"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

treehugger96

Member

Registered: 2007-12-24

Posts: 10

Re: Do we use BODMAS or not?

mabye depending on the country too

---

........"To my mind having care and concern for others is the highest of human qualities"
.........Fred Hollows

MasterofDisguise

Member

Registered: 2008-01-05

Posts: 68

Re: Do we use BODMAS or not?

I was taught it in Grade 4

---

(im an ALIEN ) im kool (WHAT You cant steal my fridge!)]

Annon

Guest

Re: Do we use BODMAS or not?

BODMAS is, i assume you are talking about order of operations?

Anonymous

Guest

Re: Do we use BODMAS or not?

Thats strange, I wouldn't expect 10 year old to be getting questions with no solutions at that age.

bossk171

Member

Registered: 2007-07-16

Posts: 305

Re: Do we use BODMAS or not?

Is BODMAS the same as PEMDAS? Is that a cultural thing?

---

There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

treehugger96

Member

Registered: 2007-12-24

Posts: 10

Re: Do we use BODMAS or not?

whats PEDMAS

---

........"To my mind having care and concern for others is the highest of human qualities"
.........Fred Hollows

bossk171

Member

Registered: 2007-07-16

Posts: 305

Re: Do we use BODMAS or not?

Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

---

There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Do we use BODMAS or not?

yes, it is the same (pretty much anyways apart from the division multiplication swap)

BODMAS - brackets, of, division, multiplication, addition, subtraction  (of being 'to the power of')

---

The Beginning Of All Things To End.
The End Of All Things To Come.

gfgfgff

Guest

Re: Do we use BODMAS or not?

BODMAS  is very important, even MS use it in their Excel package.

Rules are rules, so abide by them

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Do we use BODMAS or not?

We were taught PEMDAS but no one seems to use that anymore. Anyways, RPN is a perfectly good alternative.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.