How much does a 22 lb child weigh in kilograms?
The Correct Answer and Explanation is :
To convert a child’s weight from pounds (lbs) to kilograms (kg), we can use the following conversion factor:
1 pound (lb) = 0.453592 kilograms (kg).
So, for a child weighing 22 pounds, the calculation would be:
[
22 \, \text{lb} \times 0.453592 \, \text{kg/lb} = 9.979 \, \text{kg}.
]
Thus, a 22 lb child weighs approximately 9.98 kilograms.
Explanation:
The process of converting pounds to kilograms involves using a constant conversion factor because the two units are based on different systems of measurement. Pounds are a part of the imperial system, which is commonly used in the United States, while kilograms are part of the metric system, which is used almost everywhere else in the world, including in scientific contexts.
The reason we multiply by 0.453592 is that this is the exact weight of one pound in kilograms. This exact value comes from the international agreement on the definitions of these units. Historically, a pound was defined based on the mass of a standard object, but over time, the metric system has become more widely accepted due to its simplicity and global consistency.
When performing conversions, it’s important to ensure the units match the desired system (metric or imperial). For example, converting weight from pounds to kilograms is useful for international health measurements, especially in medical settings, where metric units are commonly used. Medical charts, prescriptions, and health reports in many countries rely on kilograms for weight measurements.
In summary, to convert pounds to kilograms, we multiply by 0.453592. For a 22-pound child, the weight is 9.98 kg, demonstrating the conversion process and emphasizing the importance of understanding unit conversions in real-world applications.