1 + 2 * 3 = 7.0
(1 + 2) * 3 = 9.0
10 / 2 - 3 = 2.0
2 * (3 + 4) - 1 = 13.0
-5 + 3 = -2.0
100 / (2 + 3) / 2 = 10.0
error caught: unexpected character '@'
