that sounds familiar. My DD does not like being put on the spot and so she may know the answer a day later, but not reveal it, but then let it all slip out in play. When I explained addition, at first she would repeat things back but I wasn't sure she really got it, then at the park she starts doing addition and subtraction with kids: there are two kids on these swings and when two more come to swing, four kids will swing...there are three girls on the top of a slide, and if one leaves, there will be two... I often introduce something to her then just leave it to simmer and eventually it all comes together. Some things she seems to get right away and repeat back, but I do sense that it goes deeper over time and sometimes it is better if I don't even bring the topic up except once in awhile.
