Least
72 ÷ 8 - 2 × (3 + 1) = 1
(72 ÷ 8) - 2 x 3 + 1 = 4
72 ÷ (8 - 2) × 3 + 1 = 37
72 ÷ (8-2) × (3 + 1) = 48
Greatest
To solve all of these, just follow the PEMDAS format (Parenthesis, Exponent, Multiply, Divide, Add, and Subtract)
Or just punch it in a calculator :)