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

(147 Posts)
Livesforbedtime Wed 05-Mar-14 18:51:11


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 confused

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 hmm ok I might be..

It doesn't make sense! angry

RedPencils Wed 05-Mar-14 21:12:18

DS1 left me behind in Year 4. He is frighteningly good at mental arithmetic and times tables. I'm shocking!
I've been known to sneak a look on the calculator on my phone, under the guise of checking a text message to check the answers.

Livesforbedtime Wed 05-Mar-14 21:14:19

Red.. That's how I knew it wasn't 406 blush

DimeBar Wed 05-Mar-14 21:31:24

I fucking hate the grid method.

I work with 16+ students doing GCSE, they're aiming for a C grade.

Give them a calculation such as 3.75 x 2.35, they get the grid correct, then give up because the numbers are too big/many to add, or they transpose the numbers incorrectly when transferring from the grid to put into columns, getting the sum wrong.

Show your kids the column method, it's so much easier in the long run.

I often wonder how scientists/mathematicians will cope in the future when half a page is taken up with one small calculation.

And breathe

Impatientismymiddlename Wed 05-Mar-14 21:35:19

Bloody chunking and gridding methods confuse us oldies who only learned the bus stop method.
I could work that out using any of the methods but my husband would struggle with anything except the bus stop method.

TheGreatHunt Wed 05-Mar-14 21:39:19

Scientist will use a calculator.

anothernumberone Wed 05-Mar-14 21:53:42

Holy crap that grid thing is complicated. I am all for exploring ways of making maths easier for students, I teach maths physics so I spend my days doing it but man that seems difficult. Do children really find it easier?

Logg1e Wed 05-Mar-14 21:56:01

The grid method is simply a precursor to the long multiplication algorithm.

BigPawsBrown Wed 05-Mar-14 21:57:43

I do not understand a word of this thread.

kim147 Wed 05-Mar-14 21:58:47

Message withdrawn at poster's request.

anothernumberone Wed 05-Mar-14 21:59:37

Logg ie not here in Ireland it is not taught here or at least dd didn't do it, thank god.

kim147 Wed 05-Mar-14 21:59:48

Message withdrawn at poster's request.

kim147 Wed 05-Mar-14 22:02:45

Message withdrawn at poster's request.

kim147 Wed 05-Mar-14 22:07:29

Message withdrawn at poster's request.

anothernumberone Wed 05-Mar-14 22:08:01

Interesting Kim I have never taught if that thankfully I get to use a calculator so I haven't had to think about it for a while. That though is far less complicated than adding a variety of different combinations of the chunks though.

kim147 Wed 05-Mar-14 22:12:17

Message withdrawn at poster's request.

DrCoconut Wed 05-Mar-14 22:18:48

I'm always amazed at how many people don't know the basics. I taught a maths session for adults once and some of them couldn't work out a simple percentage, or change from a fiver without a calculator. The same people have learned to read OK. Being basically numerate is as important is literate. Britain (in general) takes a perverse pride in poor maths skills and I can't understand it. Not blaming anyone here, we have a long term national issue with this and it will not be rectified overnight. The constant changing of methods may or may not help. It can be a good thing if a previous method was not working, or cause confusion.

I learned in Ireland in the 1980s and this is how we did it:

46 (2x3 = 6; 2x2 =4)
+460 (put a zero on the end then 2x3; 2x2)

What's that method called?

Well, I saw it was times 22. Cant do that, but I can do by times 11. So 23 times 11 is 253.

Do it again, add together 506.

kim147 Wed 05-Mar-14 22:25:37

Message withdrawn at poster's request.

Clake66 Wed 05-Mar-14 22:37:36

Lost the plot with my daughters maths student teacher or student maths teacher who set homework. Using an example with a wrong answer, so for me trying to get the homework done was impossible. I asked my A level maths husband to sort it out, who after a quick glance rather than showing her how to do it, told me to write a note to the student teacher in my daughters homework book in red "to please see me after school!" Even though she was wrong, she would not admit it! He sat and helped the next evening showing how the calculations were done in an easier way with working out shown and a further note to the head of maths to be handed in at reception.
Really annoys me that it seems only one way is allowed to get children to understand calculations they may never use again. Or have attitudes like my maths teacher that those less able won't need Pythagoras, or need to know how to calculate the area of a circle anyway....while his brother the science teacher saw everyone with the potential of the next Einstein.
Please do not get me onto teachers who cannot spell!

kim147 Wed 05-Mar-14 22:41:05

Message withdrawn at poster's request.

Nocomet Wed 05-Mar-14 22:45:49

DD2 obtained permission only to use the grid method for the first couple of questions in any multiplication HW.

DH taught her the normal column method back in Y3/4.

The grid method reduces her to a gibbering wreck. (She's dyslexic and all the neat drafting of a grid to help doesnt turn out neat and it doesn't help, it just makes steam come out her ears).

BigRedBall Wed 05-Mar-14 22:47:30

23 x

460 +
1 (carried over from 4+6 and added to the 4)

littledrummergirl Wed 05-Mar-14 22:52:44

Ds2 yr 7 asked for extra support with his maths. I bought a year 7 coursebook which has a paragraph of multiplication. 5 days ago I printed some 2figure questions of the kind above, showed him the method and sent him off to do some.

He got them all wrong!

I found the grid method today and showed him that and he told me he knows how to do it. Got the first 3 right.
I explained the proper method again writing H T U above the columns and he got them all right smile

Ds1 yr 9 at a grammar then told me he had never
seen the proper method!

anothernumberone Wed 05-Mar-14 22:53:35

Taking chances dd learned the same way this year things have not changed much.

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