Which equation would you use to calculate a casualty's weight in kilograms?

To convert a casualty's weight from pounds to kilograms, the appropriate method involves dividing the weight in pounds by a factor of 2.2. This is based on the conversion factor where 1 kilogram is equivalent to approximately 2.2 pounds.

Therefore, when you divide the weight in pounds by 2.2, you directly obtain the weight in kilograms, allowing for accurate assessment and treatment decisions in a medical context. Utilizing this method ensures that medical professionals can appropriately calculate the dosage of medications or equipment adjustments based on the casualty’s weight. This conversion is particularly important in emergencies, where precise weight measurements can affect patient care outcomes.

The other options either incorrectly suggest to multiply, add, or subtract the weight, which does not provide the correct conversion to kilograms. It's essential to remember that when converting between weight measurements, proper division using the correct factor is key to obtaining accurate results.