Maths Homework Help

[sherrardk]

Wonder if anyone can either help or point me towards a 'Math's for idiots' website.

My 12 year old son has been given an investigation to do based on the following - he has a picture of a 2 x 3 grid of squares 'made' of matches and he has to show the relationship of matches to any size of grid (presume there must be some sort of magic formula) and then he has to do the same for any size 3D grid. I don't want to do it for him (and obviously I couldn't anyway as I don't understand it) but I do want to be able to help him/encourage him, but I can't if I don't get it.

Any help gratefully received (pretty sure maths wasn't so complicated when I went to school).

[Tilly2]

I'm sure factor will be along to help soon. This is right up his street.

[sherrardk]

Hope so Tilly, didn't want to ask him directly as I don't want to hassle him and I expect there are other maths boffins here who I might offend. I haven't got a clue where to start with the stupid question.

[factor-fiction]

How many matches are in the 2x3 grid? Are the matches just round the edge (so there would be 10) or are there 4 matches inside the rectangle?

[The Builder]

Just in the spirit of "having a go" Sherrard ;o)

Since it takes 17 matches to form a basic 2 x 3 grid of squares, I guess you could see how many matches it takes to form other sized grids.
Then plot a graph of the results (number of squares against number of matches needed), and find a formula from that (if there is one)

[sherrardk]

There are matches in the grid, making 6 squares., joined together.

[factor-fiction]

Sorry, I didn't mean 4 inside, I meant 7, thus breaking the rectangle into 6 squares

[factor-fiction]

So are there 17 matches on the 2 x 3 grid?

[Tilly2]

I'm doing this with matches as we go along! 17 matches it is.

[sherrardk]

Just been and checked and there are 17 matches in total (boy #1 muttered something about having to spot patterns?).

[sherrardk]

And he's got some dotted paper (but the dots are on the wonk, so that he can draw the 3D investigation).

[factor-fiction]

There is a pattern.
He should try it himself- I think this is a great investigation.
Do squares rectangles that are
1x1 (4 matches), 1x 2 (7 matches), 1x3 (10 matches)..... need 3 more each time
Then do 2 x 1 (also 7 matches), 2x2 (12 matches), 2x3 (17 matches)....goes up in 5s

Then try 3x1 (10), 3 x2 (17), 3 x 3 (24)... goes up in 7s

Repeat. Enjoy

[sherrardk]

Thank you factor, think I will get some actual matches (the matches are for me, think I am a kinesthetic learner) and sit him down tomorrow afternoon to have a go at it (it will be quiet then as the things are at a party). x

[Tilly2]

Make sure you buy a big box of matches, sher. I've run out!

[factor-fiction]

That's a good idea. Personally I prefer to use square paper and draw lines but I know some learners prefer to use matchsticks, cocktail sticks or maybe even lollipop sticks or pencils

[sherrardk]

Think there might be something wrong with me actually - I feel the need to use matches because the question says 'matches'! Might be back tomorrow afternoon for more help.