Here's a very cute kids' video about the numbers 1-10. I don't mean to be patronising by posting so many kids' materials on this site, but I really think they're useful and fun even for adults :)
After the 1-10 song (lyrics coming shortly), there's some examples of using one "waahid" with masculine and feminine nouns (then you say "waahida").
Then about half way in, there's a song about body parts, which practices the dual. Lyrics coming shortly...