Thanks all of you!
Ash, agree with u about what language I should use for reading to him, and totally agree that it is more easy to do math in Asian language ��
Puffin, I also agree that math based toys are good.
My son asking me to use toys to teach him negative numbers, do any of you know any good toys/method to show him negative numbers? I can tell him verbally, e.g. you have three cookies but mom want to eat five, sth like that. Thanks.