Please help me with DSs maths homework (Y5)

[LynetteScavo]

Choose four numbers from the following;

1 2 3 4 5 6 7 8 9

put each digit in a 2x2 box.

This makes two 2-digit numbers reading across, and two 2-digit numbers reading down.

Add up all four of the numbers.

(for example choosing 1 2 4 & 7 12 + 47 + 14 + 27 = 100)

How many differnt ways of making 200 can you find?

(Please help, I'm feeling poorly, my head hurts just reading this homework and DH is comming home late.)

[bellavita]

Does that help Lynette?

DH said the homework should not be for Yr5 and he is not surprised that DS could not do it (Yr7) who is also in the top set for maths at school. It took some working out by DH who as I said before, uses a lot of maths for his job.

[LynetteScavo]

Thankyou!

I now have to explain this to DS - and encourage him to work it out for himself.

This'll teach me for saying "I really think he could cope with more challenging work in maths" at parents evening last week.

[squeakypop]

7138

[squeakypop]

1972 and 1792

[bellavita]

[Indrani]

Hi, do you have the derivation of these formulae? Will be good to know.

[HarveySchlumpfenburger]

Probably not since this thread is nearly 12 years old