Easy
9
+12
÷7
+1
×8
+18
HALVE
−1
÷4
SQUARE
Medium
51
+3
×1/6
DOUBLE
−7
SQUARE
+1
×1/2
−1
HALVE
Hard
43
−3
×13/5
√
−1
SQUARE
+1
×2/5
+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).