Easy
12
−6
HALVE
+8
×9
−3
÷4
−15
×8
+1
Medium
33
×3
×4/9
×2
−12
DOUBLE
−8
÷9
−5
SQUARE
Hard
72
+12
×5/7
×40%
HALVE
×25%
+45
×2
−1
×2/5
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).