Question: An animal requires $429mcg$ of drug ABC. The drug ABC comes in a $1.5mg$ tablet. How many tablets does the animal need? Round to the nearest $\frac{1}{2}$ tablet.
1. **State the problem:** We need to find how many tablets of drug ABC an animal requires if it needs $429mcg$ and each tablet contains $1.5mg$.
2. **Convert units:** Since the animal's requirement is in micrograms ($mcg$) and the tablet strength is in milligrams ($mg$), convert $429mcg$ to $mg$.
$$429mcg = \frac{429}{1000}mg = 0.429mg$$
3. **Set up the formula:** Number of tablets needed = $\frac{\text{required dose in mg}}{\text{tablet strength in mg}}$
$$\text{tablets} = \frac{0.429mg}{1.5mg}$$
4. **Calculate the number of tablets:**
$$\text{tablets} = \frac{0.429}{1.5} = 0.286$$
5. **Round to the nearest half tablet:** The closest half tablet to $0.286$ is $0.5$ tablets.
**Final answer:** The animal needs approximately **$0.5$ tablets** of drug ABC.