Easy
7
+13
÷2
−4
SQUARE
−2
HALVE
−7
×9
−13
Medium
50
DOUBLE
−1
÷3
+2
÷5
SQUARE
−15
×3
−2
Hard
110
+2
×21/2
×25%
+22
HALVE
+4
÷10
CUBE
−16
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).