What's the answer to this one ?

11 Plus Maths – Preparation and Information

Moderators: Section Moderators, Forum Moderators

Post Reply
Jim's Dad
Posts: 59
Joined: Thu Aug 15, 2013 2:03 pm

What's the answer to this one ?

Post by Jim's Dad »

18 - (9-5) x 3 = ?

To my mind there should be another set of brackets either round the 18 and the ) or the ( and the 3 - otherwise there are two possible answers surely ?

Thoughts ?
future
Posts: 168
Joined: Sat Jul 20, 2013 11:31 am

Re: What's the answer to this one ?

Post by future »

I think you would need to use the BODMAS operation for this (Brackets,Of,Division,Multiplication,Addition, Subtraction).
It has be be done in that order to get the right answer. Stand to be corrected if I am wrong :)
Ladymuck
Posts: 1240
Joined: Wed Jul 01, 2009 2:04 pm

Re: What's the answer to this one ?

Post by Ladymuck »

I'd have expected BIDMAS to apply, so brackets, then multiplication and finally subtraction.
Jim's Dad
Posts: 59
Joined: Thu Aug 15, 2013 2:03 pm

Re: What's the answer to this one ?

Post by Jim's Dad »

Oh ok, so there are rules then ?

Well that does make sense, brackets first is 4, then multiplication making it 12, then subtraction from 18 gives the supposed right answer of 6.

Better make sure my son knows this for the future !

Thanks both :)
silverysea
Posts: 1105
Joined: Fri Mar 04, 2011 3:32 pm

Re: What's the answer to this one ?

Post by silverysea »

Ask him if he's heard of Bidmas or bodmas, I was scornfully told "Of course mum, I'm not stupid!" Some time ago. But I had never heard of it myself. :shock:
hermanmunster
Posts: 12897
Joined: Fri Sep 15, 2006 9:51 am
Location: The Seaside

Re: What's the answer to this one ?

Post by hermanmunster »

I remember being taught "Bless my dear Aunt Sally" ... does that work or should the D be before the M?
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: What's the answer to this one ?

Post by yoyo123 »

D before M, so

Bless Dear Messy Aunt Sally?

Bless Dad's Miserable Aunt Sally?
moved
Posts: 3826
Joined: Fri Oct 12, 2007 1:42 pm
Location: Chelmsford and pleased

Re: What's the answer to this one ?

Post by moved »

D and M can be in either order as can A and S.

BIDMAS

Brackets
Indices (powers)
Division
Multiplication
Addition
Subtraction

Or across the Atlantic - PEMDAS
Parentheses
Exponents
Mult
Div
Add
Subtract

I like Bless my dear Aunt Sally! :)
hermanmunster
Posts: 12897
Joined: Fri Sep 15, 2006 9:51 am
Location: The Seaside

Re: What's the answer to this one ?

Post by hermanmunster »

Oh I am glad that M and D can be either way round!

can stick to the Blessing my dear Aunt Sally.... learnt from an unforgettable maths teacher :lol: :lol:
Post Reply
11 Plus Mocks - Practise the real exam experience - Book Now