Voici 5 solutions :
Solution n°1
100 - 1 = 99
99 / 3 = 33
33 + 4 = 37
37 x 6 = 222
Solution n°2
6 x 3 = 18
18 x 7 = 126
126 - 4 = 122
122 + 100 = 222
Solution n°3
7 x 6 = 42
42 x 3 = 126
126 - 4 = 122
122 + 100 = 222
Solution n°4
7 x 3 = 21
21 x 6 = 126
126 - 4 = 122
122 + 100 = 222
Solution n°5
6 x 3 = 18
18 x 7 = 126
100 - 4 = 96
126 + 96 = 222