Swimming in oodles of noodles. She cut 4 noodles and dumped them in the tub. To sneak in math have them stack the same colors and count them, sort colors in piles and see which color has the most, practice patterning...would also be cool in a kiddie pool!
This amazing idea from Mmmcrafts is perfect for boys and girls alike! All you'll need is a few scraps of felt and fur, a little elastic and a decorated drawstring bag. The templates are available in PDF format from the Mmmcrafts Etsy shop, or (if you're feeling adventurous) have a go at designing your own!
The trick to keeping kids in their beds: I've used it and it works!