Answer: Least to greatest: -0.6 -0.07 +0.09 +0.15 +0.42 and 0.15 is bigger because it is positive and 0.6 is negative.
Step-by-step explanation: What is bigger 0.15 or -0.6? The answer is 0.15 because it is positive! If the 0.6 was positive as well it would be bigger.
But when ever you have a positive and a negative no matter the numbers the positive is always going to be bigger.