The Balconia Math series is designed by professional mathematicians to challenge and entertain children with
attractive problems and games. If you want your child to develop clear logical thought, affinity for math, and
perseverance, while playing games, this series is made for you.
21 Marbles was designed by Elitza Maneva (PhD, UC Berkeley) for her 7-year old son, with his continual help. He was having fun summing "very long" numbers, but kept getting slowed down because of forgetting whether it was 6+3 that was 10 or 7+4, or maybe 6+2... (Counting your fingers while holding a pen is just not very comfortable.) The memory problem was fully resolved by this game.
21 Marbles came out to be an elegant little logical puzzle enjoyed especially by children 6-11 years old. It helps the younger ones practice arithmetic, and it challenges the older children, adolescents and adults with what is essentially a quick and relaxing peg solitaire. The puzzles are different every time you play.
As often happens, a young reviewer put it better than we can: "This is a really nice educational game, with similar skill elements to sudoku: arithmetic on small numbers and "if this then that" type logic. It's more fun, has more action and colors than other such games and so it's especially appropriate for small children."