Originally Posted by Eibbed
The counting on his fingers thing though actually seemed like it was creating a barrier to him answering, and understanding, some problems. He'd want to count on his fingers from 30 to 50 instead of using the skill, idea, that 20 is two 10s.
For my DD5, I sometimes just let her do it the slow way until she eventually discover the easier ways. I remember she used to count from 1 to 51 for 1+50. But this requires a lot patience and there is also the risk of the child getting frustrated.