My grade 4 has done a little bit of this sort of thing - I work through it with him the way that I did here. It can help to use a diagram or find five different things an do a bit of a model to understand the reasoning.
I haven't had to use factorials with him as the worksheets ask him to explain how he thought things through and I'm fairly sure he hasn't learned factorials/combinations/permutations formally.
Does the order of the flavours matter? If not, then the first poster is correct, if not, then the second poster is correct!
Ahhh, thank you! I need to brush up.
Yes, my answers assume that choc/strawberry/banana is different to choc/banana/strawberry, Secret~Sammy's solution calls those the same...
Reading the question again Secret Sammy is right because the question asks for combinations so it's implied that the order doesn't matter and choc/strawberry/banana=strawberry/banana/choc etc. Not sure how I'd help a year 4 work through that logically other than with a chart (assuming they haven't actually been taught the formula)
This post has been edited by Georgie01: 11/02/2013, 07:23 PM