2 -15 *
-3 5 7 + -
11 20 + -1 *
10 20 30 40 50 - + / *
5.5 4.5 +
-10 -2 * 100 + 1.5 0.5 + /
2 5.0 + 0 /
0 -10 / 2500 * 0 + 20 15 * *