1. The problem is to divide 0.8 by -2. 2. Write the expression as a fraction: $$\frac{0.8}{-2}$$. 3. Divide the numerator by the denominator: $$0.8 \div (-2) = -0.4$$. 4. The result is negative because dividing a positive number by a negative number gives a negative result. **Final answer:** $$-0.4$$