Oh please help me with my maths marking, I am being so thick..

[Caz10]

Disclaimer - it's a Friday night, I'm very very tired, I've been marking for 2hrs, I;ve got my period....I'm not this stupid normally...

Joe packed a large suitcase. It weighed 40kg. The case was 25% overweight. By how much was his suitcase overweight?

I think I am overthinking this - is it as simple as 25% of 40? I am thinking that I have to try to work out what original weight plus 25% of said weight would = 40kg. Pupil has just given 10kg as answer. I have no answer book. I am tired. Etc.

[Caz10]

Oh goodness when I re-read this with a non-fuzzy head I'm going to ask MNHQ to remove my thread, should have posted in Chat.

[hatwoman]

no. if it's 25 percent heaviver than it should be then 40 kg = 125 per cent of the target weight. the target weight is 40 divided by 125 times 100. ie 32 kg. so it's 8 kg overweight.

[TrinityIsLovingHerLittleRhino]

no its not

[ingles2]

Pupil is right I think, 25% of 40Kg is 10kg

[OutOfThinHair]

I take my hat off to that woman, coz she's right.

[TrinityIsLovingHerLittleRhino]

shut up you stupid woman you're no good at maths when your sober

how old is this for??

why am I so thick that I dont understand hatwomans explanation

[ingles2]

shit have I got that wrong... I have,.. now you've said it you're right hatwoman

[fucksticks]

yes hatwoman correct

[kalo12]

no its 10kg overweight.

it doesn't say it is 25% of the weight limit overweight, just it is 25% overweight

[MillyR]

Hatwoman is right.

Tis a classic 11 plus type question.

[MelonCauli]

Yup, 8kg because it has to be 25% of its original weight

[frAKKINPannikin]

Case weighed 40kg
It was 25% OVERweight so 125% of original weight
40kg divided by 5 = 8kg, mutliplied by 4 to give original weight = 32kg
40-32 = 8kg overweight

Pupil is not right. Pupil has fallen into the clever trap!

[TrinityIsLovingHerLittleRhino]

this isn't 9 year old homework is it
cause if it is I'm screwed

[Caz10]

hatwoman said what i tried to say in my 1st post only much much more clearly! That is what I thought you'd have to do, but then I thought I was over-complicating things. Thank you!

Have just had argument with DH over this who thought the answer was 10kg. Ha!

This is for Yr6 - and not even my top group - you should see when I try to do the marking for THEM when I'm overtired!

[hatwoman]

I do, though, agree with kalo - the problem is badly worded, but I can't see what else it means.

[Caz10]

Oh I am so glad to see it is not just me who is confused.

[TrinityIsLovingHerLittleRhino]

oooh I get that
25% is a quarter so we know that there is 5 in the whole weight......

so divide weight by five for the amount it is overweight

[MillyR]

I really recommend the Peter Robson maths books for this kind of stuff. Every other page gives clear instructions on how to solve each different type of maths problem. It makes everything seem really straightforward.

[QuintessentialShadows]

32. it was overweight by 8 kg

[Caz10]

Thanks MillyR I will have a look for them.

[QuintessentialShadows]

sorry, did not see that it had already been worked out.

I dont follow the reasoning, I fed it into my percentage formula in excel.

[Caz10]

Out of curiosity would you advise a pupil to do:

40/125 * 100 etc

or

40/5 * 4 etc?

[Caz10]

QS that's cheating!!

(says me, marking Yr6 maths with a calculator )

[MillyR]

They are called Peter Robson maths for practice and revision. They certainly wouldn't suit every type of child as they are old fashioned, but they really helped my son and are useful for adults wanting to look things up.

[frAKKINPannikin]

Errrm as it's a percentage I'd say 40/125100 but I hate percentages and always think things through in fractions hence using 40/54