smallest to largest :

squareroot15 , -2.6, -8^2, 5/8, 2 3/4,4.1 , 3.14

is this the correct order: -2.6,5/8,2 3/4, 3.14,4.1,-8^2

the way you wrote -8^2

would give you -64

(-8)^2 = +64