The correct answer is: $0.5$
Explanation
To convert the fraction $\tfrac{1}{2}$ to a decimal, divide the numerator by the denominator.
Steps:
- First step: $$1 \div 2$$
- Second step: Write $1$ as $1.0$ to perform decimal division: $$1.0 \div 2$$
- Final step: $$1.0 \div 2 = 0.5$$
Therefore, $\tfrac{1}{2}$ as a decimal is $0.5$.