Easy
12
×8
−6
÷9
SQUARE
−14
HALVE
+8
÷3
−10
Medium
54
×2
−10
×1/7
HALVE
+5
×2/3
SQUARE
−19
×3
Hard
83
−8
×2
×90%
−3
÷12
+1
×31/3
+20
×10%
There are two versions that can be printed, a default one, and one that requires less ink (no objectives or rules, and no lines).