My friend's toddler (21m) can count to 10, with a couple of numbers skipped and she'll remind him and he'll continue from the skipped number. She'd like to know if this is advanced or just a good memory please?

Excellent advice, Portia, as usual!

Doesn’t really matter, to be honest! She can make almost anything into a game to delight her child. If he enjoys numbers and quantities, he will devour the play with a vengeance.

Math my DS liked at that age:
- Drawing simple number lines in chalk and hopping along them, like hopscotch, while I barbecued. I’d call out something like, “Hop 3 more than 2.”
- Building Duplo structures for toys (Shleich animals, Playmobil figures, blocks)
- Making 3-D shapes with Magformers
- Playing with interlocking unit cubes
- Simple tesselations and mazes
- Sorting small food items with scoops, measuring cups, tweezers, and scales
- Rhythm play with music: simple structures
- Sensory play: sand, water, beans, rice, kinetic sand, etc. Drawing lines, shapes, quantities, comparing volumes / sizes.

Math is a universal language, and children are naturally attuned to its delights. The trick, if it is one, is to watch the child’s face. If you see elated smiles, giggling, and lots of happy repetitions, keep going! He’ll consume whatever he enjoys, and an enthusiastic play partner can make almost anything interesting.

In case this may be of assistance to your friend, here is a link to a brief roundup of links describing common behavior characteristics, traits, and early milestones which may indicate giftedness in infants, toddlers, preschoolers, young children. (This list may be especially useful before IQ test scores tend to stabilize, around 8 years old.)

http://giftedissues.davidsongifted....p_of_traits_is_my_baby_o.html#Post248478