My 7 year old daughters Maths homework is beyond me...

[Beetrootccio]

can you do it and if so tell me how

Parcel V is 1/4 kg lighter than x
Parcel W is 1/2kg heavier than v
parcel x is half the mass of z
Parcel y is double the mass of v
Parcel z is 1 1/4 more than X

What is the mass of each parcel

I would NEVER believe me with equations by the way

Twiglett,

Parcel x is half the mass of z, i.e
x = z/2
or
z = 2x

(not the other way round)

I am RIGHT in thinking that mass is not exactly equivalent to weight though aren't I?

I'm going to try that again

Parcel V is 1/4 kg lighter than x means X = V - 0.25kg

Parcel W is 1/2kg heavier than v means W +0.5 kg = V

parcel x is half the mass of z means X * 2 = Z

Parcel y is double the mass of v menas Y = 2 * V

Parcel z is 1 1/4 more than X means Z + 1.25kg = X

is that right?

I'm loving this thread.

I am making no attempt whatsoever to follow it but I'm really loving it.

just trying to imagine how someone could have thought this was an appropriate exercise for a 7 year old....

Twiglett, you are right about the mass/weight issue, but I don't think it should be a problem in this instance, unless Parcelforce is routing its deliveries via the moon (I wouldn't altogether put it past them, mind you...).

The equations are:
v = x -0.25
w = v + 0.5
x = z/2 (or 2x = z)
y = 2v
z = x+0.25

So your first, second and fifth are incorrect.

I do agree, btw, with those saying it's not a good exercise for a seven year old. After all, they're not taught algebra (which we're all using here ) even by Year 6. There are some questions in the Year 6 SATS that call for algebra, but DS1 and classmates were told to do them by trial and error (He rebelled and showed others how to do them sensibly [why no proud mother emoticon]).

I used to be good at maths .... ROFL

I got:

V=1
w=1.5
x=1.25
y=2
z=2.5

BUT I have a degree in accounting, worked for banks for 7 years in management accounting (so basically spent my life number crunching and staring at excel spreadsheets!).

There is NO WAY I could have done those maths at 7 yo!

I think it is difficult for a 7 year old, as they would find it hard to know where to start.

But it is actually very easy to work out, as we know that X is half Z and that Z is 1.25kg more than X ie Z = 2 x 1.25 kg. And once you know those 2 all the others fall into place.

I'm presuming that your dc's school isn't for child geniuses who would appreciate the difference between mass and weight at the age of 7. This would have completely thrown my engineer DH who would have tried long algebraic calculations to reconcile mass and weight.
However, it is a difficult problem for a 7 year old - it is the type of question that comes up in verbal reasoning tests for entrance to selective schools at 11 or 13.

If either of mine came home with this i would cry

Oh my sweet aunt fanny Beety that's terrifying. Mind you, ds has been whingeing about his maths (also Yr3, top "set" FWIW but nowhere this level!) so I think I might set him that problem tonight and then get him to thank heavens he's not at your dd's school.

v+0.25=x
w-0.5=v
2x=z
y=2v
z-1.25=x

2(v+0.25)=z
2v+0.5=z
z-1.25=z/2
2z-2.5=z
z=2.5

2v=2.5-0.5
v=1

v+0.25=x
1.25=x

w-0.5=v
w-0.5=1
w=1.5

y=2v
y=2

So

x=1.25
v=1
z=2.5
w=1.5
y=2

Does that look right?

Definitely too hard for age 7 though! I've got A level maths and had to think hard!!!

And now Tortoiseshell has worked out the answers (Waynetta I know you did too but my brian froze over with all those quarters ) I can pretend I knew too

Batters, my Y3 ds would have not the remotest idea how to do this, and I would be horrified if he came home with this stuff. Poor little chap has only just understood the notion of working out change from £1, and has only half-grasped the connection between 6.45 and quarter to seven. And he's considered reasonably good at maths, in a reasonably able class.

marina!

But you don't need to do it with formal algebra, do you? I mean, you can. But it's much simpler just to start off with the facts you know and then add and take away for the other answers.
You start off knowing that X is half the mass of Z and knowing how much more Z is (1.25 kg) so you know that Z is 2 x 1.25 and X = 1.25 kg. So:

X= 1.25
Z= 2.5
V is 0.25 kg less than X, so = 1.00
W is 0.5 kg heavier than V so = 1.5
Y is twice V so = 2.00

It is definitely hard for a seven year old. But you certainly don't need maths A-level to do it!

It is really more of a logic puzzle than a maths puzzle.

Yes but the real questions are

A) Which ones can you spend by Standard Parcel Force and which ones will need "over-specified weight" status?

B) Statistically how likely is it that the post office depot will be closed the only afternoon you have 10 minutes free to go and collect them?

Please show all workings.

I have a arents evening tomorrow so I will have a chat with them -

now can you solve this problem for me