20 is the atomic number for calcium. This is essential for good bone health. Think about giving your giftee some calcium-rich dairy products (eg: ice cream) or doing a weight-bearing activity that increases bone density (eg: soccer).
20/20 is associated with perfect vision. Give them some sunglasses or something to look at using their 20/20 vision (eg: theatre, artwork).
Score = 20 (eg: fourscore and seven years ago…). Work in a scoring activity here (eg: sports events, board games)
Have your giftee guess their gift using 20 questions.
The 20th century is associated with many great inventions and events. You can use these to work in gifts (eg: space exploration began in the 20th century-take your giftee stargazing, watch a movie about space)
