Easy
18
−2
÷8
SQUARE
+11
×5
+15
÷6
+9
HALVE
Medium
40
−3
DOUBLE
−4
×2/5
×4
−8
HALVE
−18
×2
Hard
68
+2
×3/7
×5
×30%
+47
×25%
+3
×8/13
SQUARE
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).