Easy
5
+10
×5
−1
÷2
+3
÷4
+8
HALVE
−3
Medium
18
DOUBLE
−19
×3
−17
÷2
−11
×5
−16
×7
Hard
54
+11
÷13
+47
×25%
SQUARE
−1
÷14
×2/3
×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).