In not being able to do my 10 year olds math homework!

[Livesforbedtime]

I don't understand this.. She has to work out 23 x 22..

Now I'm not the sharpest pencil in the box, but I have a degree and a responsible job... So WHY when I worked it out as:

20 x 20 = 400
2 x 3 = 6

Answer = 406

But it's not is it? It's 506.. But I don't understand why

My poor 10 year old DD is bewildered.. And I cannot understand why I'm wrong yet I know I am!

I suspect it have a mind block... Yes that's it.. I'm not truly stupid ok I might be..

It doesn't make sense!

I taught a maths session for adults once and some of them couldn't work out a simple percentage

I'll never forget interviewing 15 graduates for a post requiring mental arithmetic. We hired the ONLY one who could tell us 15% of 100! We got so excited that she could do this - having failed to realise we'd need to dumb down the questions like this - we moved along to 75% of 80. Which she couldn't do. She got the job anyway.

I do chunking & gridding in my head, and thanks for giving me names for it I check my answer with columns & bus stops.

Don't understand what you lot are on about, never seen all that stuff only DarlingGrace knows how to multiply
Dcs are 14 & 13 they never did this, is it new?

Garlic, DS who is nearly 9 has just been able to tell me 15% of 100 (he looked at me like that was a trick Question or I'd gone mad! ) and then 15% of 200 and 15% of 50. He barely had to think about it.

The trouble is that a large % of kids/teens/adults never grasp that % actually means PER HUNDRED

I once had someone who just did not get that 80% of 80 was NOT the same as 80% of 100. She was going , but it's the same because 80 per cent is 80 per cent regardless of what it's out of

It's sad, IMO.

Garlic that reminds me of doing a compulsory accountancy course during a law postgrad. The tutor was pointing out that arithmetic isn't scary and showing that there are patterns to it. "So what's 10% of 100?" he says brightly to one woman. Blank look. Eventually someone says ten (that might have been me). "Great," he says, now with a slightly forced smile, "And 35% of 100 is…." Blank stare. Eventually the same person says 35. He goes back over it, in the tone you'd use to a four year old, "so if TEN percent of one hundred is TEN, and THIRTY FIVE percent of one hundred is THIRTY FIVE, who can tell me what SIX POINT SEVEN FOUR percent of a hundred is?" Blank stares. Cringe.

My dd got 98% on her homework..

She blatantly doesn't get it from me

Gawd, Posy. This nation is a grifter's paradise, isn't it?

At least your DC won't get ripped off every time they open their wallets, phantom and Lives! :)

Kin147, in reference to "So being able to be a whizz at long division / multiplication does not help you unless you understand the problem." I would disagree.

Knowing the basic arithmetic certainly does help. As you point out, understanding a problem and being able to put it into a mathematical expression is also an essential skill. But, you will need the arithmetic skills as well.

I prefer teaching long division to children because it shows them the full picture and helps them understand why they are doing what they are doing. DD (year 6) does this weird shorthand version of long division. She gets on fine, and gets the answers right. My 8 year old is just learning this stuff and is totally confused by her method. SO I am teaching him the good old fashioned long division because it always works.

DS and I developed a little chant to remember it last week. Perhaps some others would find it useful.

1. How many?
2. Multiply
3. Subtract
4. Bring it down! (down with a gesture of a fist and elbow pulled back to the hip as you you say "DOWN!")

Another tip I have is that when you or the children get overwhelmed, remind your selves that complicated math problems are merely a series of simple ones.

And last but not least "Math is fun... And don't you forget it!" :-)

I have often done long multiplication without a calculator, sometimes because dd has borrowed it so I can't use it, sometimes because I can't be bothered to get up to go and get it, sometimes because I'm out and my calculator's at home. I assume that I shall continue to do so quite often until I die. There are all sorts of every day things which long multiplication can help with.

I learnt in the early 60s, so use the column method.

Last year DS (then year 4) claimed not to know how to do his multiplication homework so I showed him the "traditional" method because I am old

A couple of weeks later we had a tutorial at school to show us the methods they use. Wouldn't it have made more sense to show us before setting it as homework?

I am an accountant so am numerate, I "cheat" by making an easy sum them correcting the difference, I never realised this was a method, I just thought I was lazy!

Polkadots, i'd do it your way too. Find an easy sum that is nearly what the question is, get the answer to the easy sum then adjust the answer to get to the question asked.

Kim that is the question if I have to get 1/2 of a 1/5 we were taught to turn the second number upside down and multiply. It was literally only this year I questioned what was going on. Linear algebra, differential calculus, multiple derivatives I totally got but I never questioned why I would turn the nominator and denominator in their head go figure.

I can explain it now too without algebra ;-) only caused I asked myself why I was doing it.

Eh? What are you turning upside down?

Half of a fifth is a tenth, isn't it? ... Is it??

Ah! Phew

Yep said it wrong oops bad me.

Call me old fashioned but this 'new-fangled' way they learn maths - I think - leaves greater margin for error.