Kids learn the piano differently, and process information differently from that of an adult. Therefore, you cannot teach them the way an adult would. Neither should the piano teacher you engage teach them like how they usually teach adult students of the piano!
Check out the following video if you want to know how to teach your kid the piano. If you have engaged a private home piano teacher in Singapore to teach your child, then make sure they are teaching them in a similar style to the tutorial in the video below to ensure that your kid plays and learns the piano the best way. Here is the Facebook page of a local agency which matches you up with the best private home piano teachers in Singapore.
It is important to understand and accept that people of different ages learn the piano differently. To enable your child to be the best pianist he or she can be, make sure to engage a piano teacher who understands this key point and how to teach kids the piano.