Teacher marked correct work as incorrect

[MillionToOneChances]

This has been happening a lot lately, but today feels worse as the school's maths coordinator was taking the lesson. My DC had written that 36 was the square root of 1296. Maths coordinator marked it incorrect and said the correct answer was 936.

AIBU to be really frustrated? These incidents are really knocking his faith in school. I know he's a kid and the teacher is just a human being, but my DC does have form for being unfeasibly good at multiplication so a little faith wouldn't have gone amiss if it wasn't an easy sum for the teacher.

[partialderivative]

I once corrected a maths teacher.

What did s/he do wrong?

[Marcipex]

What was wrong....
They had drawn a shape on a graph, then enlarged it.
So the shape was 6 cm by 6cm. Then the length and height were doubled, so 12cm by 12 cm.
'So the area is doubled' wrote DS.

No, not doubled, you've squared it ' etc I said.
DS insisted they had had to write doubled. i just thought he hadn't been listening.

[MillionToOneChances]

marciplex I hesitate to risk correcting you but neither you nor the teacher are correct.

Not sure how I'd express it, but the area can't be squared because - coincidentally - the original 6x6 square has an area of 36cm2. As established in the OP 36 squared is 1296. A 12x12 square would have an area of 144cm2

[Marcipex]

Sorry OP, I'm not sure what you mean. I am not great at maths.

But I made up the numbers there as an example.
The length along each axis had doubled. But the area isn't doubled if you double the length of the sides, the area is more than doubled.

Iyswim

[sanfairyanne]

as this is primary maths its probably lack of subject knowledge

you can ask to speak to the teacher and explain
adv = other kids will not be taught nonsense
disadv = teacher will probably have big strop

or you can tell your child noone is infalliable and the teacher got it wrong

i have tried both options. hard to say which is least worst option

[MillionToOneChances]

The area is quadrupled because the two sides have both doubled.

[AuditAngel]

Can I ask a question please? I have just been told DS is being extended in maths with a view to reaching level 6 in his SATS in the summer in year 6. How does this compare to "average"? It is too long since I was at school to know what this means, plus I think I was on gifted and talented for maths anyway.

[PenelopePitstops]

I'm confused now by the question. The length of the 6cm square sides have doubled?

Where does the 36 come from?

[MillionToOneChances]

My problem is that maths is hugely important to him so if they don't set him challenging work (they don't) and don't even understand what they are teaching the others, he gets very frustrated.

I've asked for an appointment to go in and speak to her, but based on this issue today and various others (and lots of comments here) I don't think his current teachers are equipped to challenge him in maths. We don't want him to go ahead of what they've been taught, but his capacity to use what he does know fluently and imaginatively far exceeds theirs (and mine, but I have time to read up and get suitable work for him). The sad thing is that this is the first time this term he's been set the kind of open-ended question he should be doing loads of, and he was thrilled til the public (and inaccurate) "close but not quite" in front of the whole class. Then he was still buzzing but half with indignation!

[MillionToOneChances]

audit average for year 6 is level 4b. My daughter who was towards the top of the top set was put in for level 6 but got a 5a. Level 6 is secondary school curriculum.

penelope the area of a 6x6 square is 36

[MillionToOneChances]

These days, at our school at least, usually at least the top set of top table is put in for level 6 papers. Teachers feel free to correct me.

[MillionToOneChances]

Oops, top table of top set!

[Marcipex]

Sorry Penelope, I just made up an example. It's caused more confusion.

The teacher insisted squaring a number was the same as doubling it.

Only if that number is 2 I said.

She said I was unnecessarily complicating the issue.

But I hadn't challenged her in the first place, I'd only challenged DS.
She harangued me in the playground after school, and every time she saw me for two more terms.

[teacherwith2kids]

I well remember my year 6 Maths teacher, who I routinely corrected. Luckily she was SO hopeless at maths hat she quite liked it that she could rely on me for a correct answer....

Only tried it once at secondary. Teacher was a) not impressed that I had even thought to question her and b) lost no time in proving me wrong...

[MillionToOneChances]

Teacher he's desperate to fast-forward to secondary and a teacher with a maths degree!

[DadDadDad]

I was a secondary school maths teacher (which is probably why I got a bit carried away doing some extension work with your DS!), and that's one of the things I love about the subject: that you can prove the teacher wrong. I would have actually welcomed a bright student who could spot my mistakes. Things are not true because an authority asserts them, even the greatest professor in the world; they are true because the logical steps for proving them have been set out and anyone with enough knowledge can verify them.

[MillionToOneChances]

I guessed, DadDad! I've been hoping to get my MIL to exercise her professional expertise similarly, but she doesn't seem very keen. If she'd only do it face to face and see how his lights up, I'm sure she'd be hooked!

I'd better work with him on tactful techniques for setting the teacher straight. Maybe.

[DadDadDad]

Well, there's always: "can you show me how you got that answer?" (and that's a pupil asking a teacher, perfectly sensible if the teacher wants pupils to grasp the ideas for themselves).

Or in this instance "how does the square root button on the calculator work?"

[Thumbwitch]

It doesn't stop at school, either. :(
My forte was chemistry (not so much now, I've probably forgotten most of it!) and both at university and at a training college I've had to tell the lecturer that they've made mistakes - one on his version of the periodic table, where he'd written the wrong symbols for boron and beryllium (should be B and Be, he'd written Bo and B respectively); and the other for having the incorrect formula for sulphurous acid, in an equation, which then didn't balance correctly at all because the formula was wrong. I was only 18 for the first one so put my hand up and challenged in front of everyone (but I was right and he acknowledged it) - but a fair bit older for the second one so told the teacher in the lunch break, she changed it afterwards.

[MillionToOneChances]

Ohhhh, so simple and literally perfect. Thanks.

"Can you show me how you got that answer?" they're going to hate him, aren't they?!

[DadDadDad]

In the meantime, if your DS enjoys Maths, he should find plenty here (games, puzzles, problems, discussions) to get him interested:
nrich.maths.org/frontpage

[MillionToOneChances]

Thanks for the nrich link, but I can't seem to get him going on computer maths games, apart from DragonBox Algebra which we both love. He prefers to do everything in his head, or maybe a scrap of paper.

[DadDadDad]

Ooh, now you've got me intrigued: when was ExH at Cambridge? (I studied Maths there too).

My children are reasonably able at Maths, but I've never been able to get them really interested in it - they appear to be into other things.

[DadDadDad]

nrich is more than games - sorry, if I've been misleading; they regularly set maths puzzles that I think are all about doing it on a scrap of paper (mentally imagined or real). I'd have a look yourself before you dismiss it.