Here are some useful links to online number activities.
For numbers 1-10:
http://www.education.vic.gov.au/LanguagesOnline/indonesian/sect03/
For numbers 11-20:
http://www.education.vic.gov.au/LanguagesOnline/indonesian/sect05/index.htm
For numbers 20-100
http://www.education.vic.gov.au/languagesonline/indonesian/sect25/index.htm