Answer: The number is 0
Explanation:
We want to find a whole number and its oppposite between -0.5 and 0.9
first, a whole number is an integer number, and the opposite of the number a is equal to -a.
Then the only possible solution is 0.
Because 0 is a whole number and it is the range of -0.5 and 0.9
and the opposite of 0 is -0 = 0.
So 0 is its own opposite, then the opposite of 0 is also in the range -0.5 and 0.9