As a tribute to the old school, can you build a Calculator? It should support all 4 operators (+ - x /).
Difficulty: Hard
For example: "408+3897=" should result in 4305, “12-35=” should result in -23, “9x16=” should result in 144, "36/9=" should result in 4 and so on.
Looking for a bigger challenge? Try the to add more calculator functions.