Question

An infant's head circumference is \(40 \mathrm{~cm}\). How many inches is this? _______ \(\mathrm{in}\)

Short answer

40 cm is approximately 15.75 inches.

Step-by-step solution

Understand the Conversion Factor

To convert from centimeters to inches, we need to know the conversion factor. The standard conversion factor between centimeters and inches is 1 inch = 2.54 cm.

Set Up the Conversion Equation

Using the conversion factor, set up the equation to convert 40 cm to inches. This is done by dividing the number of centimeters by the conversion factor: \[ ext{Inches} = \frac{40}{2.54} \]

Calculate the Conversion

Calculate the result of the equation from Step 2. By dividing 40 by 2.54, we find: \[ ext{Inches} = 15.748 \] So, 40 centimeters is approximately 15.748 inches.

Round the Result

We typically round the result to two decimal places for simplicity unless specified otherwise. Hence, 15.748 inches rounds to 15.75 inches.

Key concepts

Infant Measurements

Measuring an infant is a fundamental task for tracking growth and development. These measurements typically include weight, length, and head circumference. Each measurement gives insight into different aspects of a baby's health and development. Head circumference is a key metric that indicates brain growth and overall well-being. Knowing how to measure these parameters accurately and consistently is important for healthcare professionals and parents alike. Understanding these measurements helps ensure that a child's growth follows a healthy pattern and allows for early intervention if any abnormalities are detected.

Head Circumference

Head circumference is a crucial measurement in infants that helps monitor the growth of the baby's brain. This measurement involves wrapping a flexible tape around the largest part of the head. Typically, this is done around the forehead and above the baby's ears. Regular measurement of head circumference assists in tracking developmental milestones and is part of routine health screenings for infants. A steadily increasing head circumference is usually a good sign, indicating normal brain development. However, significant deviations from the normal range can be indicators of health issues, necessitating further investigation.

Metric to Imperial Conversion

Understanding metric to imperial conversion is essential, especially in countries that use the imperial system. In this exercise, we are converting head circumference from centimeters (metric) to inches (imperial). Knowing that 1 inch is equal to 2.54 centimeters is vital to performing accurate conversions. Using this conversion factor, we can translate measurements easily:

• To convert centimeters to inches, divide the number of centimeters by 2.54.
• Conversely, to convert inches to centimeters, multiply the number of inches by 2.54.

Familiarity with these conversions ensures that measurements are understood universally, regardless of the measurement system used.

Division in Calculations

Division is a fundamental mathematical operation used in various calculations, including unit conversion. In this exercise, we used division to convert from centimeters to inches. The formula is simple: divide the length in centimeters by the conversion factor (2.54) to obtain the length in inches. For example, to convert 40 cm to inches, the operation is: \[ \text{Inches} = \frac{40}{2.54} \]This type of calculation is straightforward and essential for precise unit conversion. Proficiency in division helps in many everyday tasks, making it a valuable skill to master.