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Use of brackets

Posted: Fri Oct 31, 2008 11:00 pm
by clarendon
My 9 year old son has been set some maths for the half term. It involves using brackets to obtain different answers using the same set of numbers. He's struggling with them and I'm baffled!

One q is : insert as many brackets as you need to make this calc. total 100 with both calculators:-
4 + 1 x 8 + 3 - 6 x 3 x 2 - 2

Please can someone tell me what is meant by both calculators and what is the method used to solve this sort of problem? We've tried all manner of combinations and failed to reach 100.

Son says he was given this by a supply teacher on the day they broke up and was given no advice on what to do other that the acronym BIDMAS.
I'd appreciate any enlightenment please!!

Re: Use of brackets

Posted: Sat Nov 01, 2008 12:43 am
by SunlampVexesEel
clarendon wrote:My 9 year old son has been set some maths for the half term. It involves using brackets to obtain different answers using the same set of numbers. He's struggling with them and I'm baffled!

One q is : insert as many brackets as you need to make this calc. total 100 with both calculators:-
4 + 1 x 8 + 3 - 6 x 3 x 2 - 2

Please can someone tell me what is meant by both calculators and what is the method used to solve this sort of problem? We've tried all manner of combinations and failed to reach 100.

Son says he was given this by a supply teacher on the day they broke up and was given no advice on what to do other that the acronym BIDMAS.
I'd appreciate any enlightenment please!!

( 4 + 1 ) x ( 8 + 3 - 6 ) x ((3 x 2) - 2)

Isn't it BODMAS but there does seem to be a http://www.mathagonyaunt.co.uk/INTERACT ... ation.html

Posted: Sat Nov 01, 2008 9:50 am
by Wallasey
Yes it used to be BODMAS but now is BIDMAS! It stands for

Brackets
Indices
Division
Multiplication
Addition
Subtraction

meaning do anything in brackets first, then indices if there are any, etc.

No idea what 'both calculators' means though.

Posted: Sat Nov 01, 2008 1:21 pm
by Guest55
Both calculators, I suspect, refers to the 'old fashioned' type that did not always get the 'right' answer because they worked from left to right rather than using BIDMAS and the newer ones that do.

It sounds like a homework that was not really thought through ..

Posted: Sat Nov 01, 2008 2:44 pm
by clarendon
Thanks for the help... had no idea that "double" brackets could be used!
You're right Guest 55.. as I said the homework was given on the Fri they broke up and by a supply who didn't offer any explanation. It's from a Scholastic paper aimed at 9 - 11 yr olds.