Yr 5 DD doing reasoning test type things ... ambiguous maths question...

[GrimmaTheNome]

One question I'm not sure what answer they are looking for. They are given letters and values eg
a=1 b=2 c=4 etc and then have to work out some sums eg a+c = ...5, obviously.
c/b = 2, fair enough.

But then there was 2a-1 and bc - a.

Bearing in mind this is Yr 5, and I don't think they've done a right lot of algebra yet, would you say these are supposed to be
21 -1 and 24 -1 (substitution of letter with number) or - as I automatically assumed -
2x1 -1 and 2x4 -1

DD thinks the former - that may be what they are expecting, but if a child had been exposed to any algebra they'd see it as the latter ... confusing, huh?

latter

I would assume the latter, but I think your dd should do it the way she thought of it, then the teacher will be alerted if that's not what she meant.

I agree it's ambiguous though.

It is definitely 2xa - 1 and 2x4 - 1.

Can she not give both answers - and label them 'my way' and 'my mums way' and see which is marked right. At my dds school we just have to mark down which bits of the homework we've 'helped with' - ie done for them!

I think that if it is reasoning rather than algebra then it would be the former.

Just to muddy the waters.

Maths is lovely, but illogical!

No room on sheet for multiple answers! I've stuck in a post-it asking if they've covered this sort of problem before - some of it was evidently types DD hadn't seen before but she could work out what to do with those clearly enough.

If it's reasoning, a verbal reasoning paper, I think it is likely to be the latter. It seems to be standard on every VR sheet I've ever seen. Unfair, if dd hasn't come across it written that way before, but I think that is quite standard with reasoning papers.