Do you pay attention to the age recommendations on kids toy packaging? Personally, I dont. If it has small pieces that look like they might break off, I wont give it to my kids. A puzzle is a puzzle. Yes some maybe harder than others but its still a puzzle with large pieces, does it matter if it says 4+?
This brings me to chalk. The package says that it is 3+. The twins are just over 2 and I cannot see any reason why they cannot play with chalk just because they are not 3. So what if they eat it draw on the wall, isnt that the point? Besides that, they love to draw so why not let them go to town on the sidewalks.