Easy
18
−12
×9
−15
÷3
−6
SQUARE
−13
HALVE
+3
Medium
50
DOUBLE
+2
÷6
−1
×1/2
SQUARE
HALVE
−2
÷3
Hard
16
HALVE
CUBE
+20
×25%
−3
÷10
SQUARE
−7
÷9
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).