This is your 4.5yo, is it, MamaJA? That's a tricky age for asking for harder maths if it isn't your thing, since (I suppose?) she's not likely to be up for being handed a book yet. Do look at the Sir Cumference books and that kind of thing, though; encourage her to play with numbers and look for patterns in what happens when you add this to that (evens, odd) or multiply this by that... Get her to see what shapes she can make that tessellate, i.e. that fit together and cover as much floor as you like with no gaps... Explore arithmetic in different bases (where instead of bags of 10 you have bags of something else, e.g. "17" in base 8 means 1 bag of 8 plus 7 units = 15 in base 10". Etc... If you want ideas for exploring particular directions that interest her, just ask - there are plenty of people who like to talk about maths here!
