Easy
18
−8
HALVE
+4
×8
−18
÷2
+3
÷5
+19
Medium
24
HALVE
−2
×1/5
×2
SQUARE
×9
−11
DOUBLE
−18
Hard
99
+9
×25%
−3
×5/8
+3
÷9
CUBE
×5
×30%
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).