Question

A baby weighed \(4.85 \mathrm{~kg}\) at birth and now weighs \(7.9 \mathrm{~kg}\). How many kilograms did the baby gain? ______

Short answer

The baby gained 3.05 kg.

Step-by-step solution

Identify Initial and Current Weights

The initial weight of the baby at birth is given as \(4.85 \mathrm{~kg}\). The current weight of the baby is \(7.9 \mathrm{~kg}\).

Calculate the Weight Gain

The weight gain can be determined by subtracting the initial weight from the current weight. This can be calculated as follows: \(7.9 \mathrm{~kg} - 4.85 \mathrm{~kg}\).

Perform the Subtraction

Calculate the difference: \(7.9 - 4.85 = 3.05\). So, the weight gain is \(3.05 \mathrm{~kg}\).

Key concepts

Understanding Subtraction

Subtraction is a fundamental mathematical operation that involves taking one number away from another. It's a straightforward concept that occurs in many real-world situations, such as calculating weight gain, like in our exercise.
When you subtract, you're essentially asking: How much more is one number than the other?

• The number from which you subtract is called the "minuend," and the number that is subtracted is the "subtrahend."
• The result is known as the "difference."

In the exercise, the baby's current weight is the minuend, and the initial weight is the subtrahend. By solving the equation, we find the difference, representing the weight gain. With subtraction, it's essential to align decimal points correctly to ensure precision.

Problem Solving in Weight Calculation

Problem solving is a critical skill in mathematics, allowing us to tackle real-life challenges, such as calculating weight changes over time. In our example, we are determining how much weight a baby has gained since birth.
This involves a few key steps:

• Identify the values involved, here, the initial and current weights.
• Determine how to manipulate these values mathematically to solve the problem (using subtraction).

By breaking down the problem into these manageable parts, you can easily calculate the weight gain. Practicing problem-solving skills enhances your ability to approach various challenges methodically.

Step-by-Step Solution Approach

A step-by-step approach is beneficial for solving mathematical problems, as it assures accuracy and clarity. Let's look into the structured method used in our example:

• Step 1: Identify the given initial and current weights of the baby. Knowing these values accurately is the foundation of your solution.
• Step 2: Understand and decide on the necessary operation, which in this case is subtraction, to find out how much weight the baby has gained.
• Step 3: Execute the subtraction precisely. You calculate: \(7.9 - 4.85 = 3.05\).

Following such step-by-step methods not only makes the solution easy to follow but also reduces the chances of overlooking essential details. Practice regularly to get comfortable with this approach.