Question: According to a model, the head width, in millimeters, of a worker bumblebee can be estimated by adding $0.6$ to four times the body weight of the bee, in grams. According to the model, what would be the head width, in millimeters, of a worker bumblebee that has a body weight of $0.5$ grams?
1. **State the problem:** We need to find the head width of a worker bumblebee given its body weight is $0.5$ grams.
2. **Formula:** The model states that the head width $H$ (in millimeters) is given by:
$$H = 0.6 + 4 \times W$$
where $W$ is the body weight in grams.
3. **Substitute the given value:**
$$H = 0.6 + 4 \times 0.5$$
4. **Calculate the multiplication:**
$$H = 0.6 + 2$$
5. **Add the values:**
$$H = 2.6$$
6. **Interpretation:** The head width of the worker bumblebee with a body weight of $0.5$ grams is $2.6$ millimeters.