Problem 53 - Algebra 2

Question

Find each percent. 99% of 400

Step-by-Step Solution

Answer

99% of 400 is 396.

Step 1: Convert Percent to Decimal

To find 99% of a number, first convert the percent into a decimal. Percent means per hundred, so divide 99 by 100 to convert it to a decimal. This gives 0.99.

Step 2: Multiply Decimal by the Number

Now that we have the decimal form of the percent, multiply it by the number we are finding the percent of. Multiply 0.99 by 400 to get the result: \[0.99 \times 400 = 396\]

Key Concepts

convert percent to decimal

Converting a percentage into a decimal is an essential math skill often used in solving problems involving percentages. A percentage represents a part of a whole, specifically per 100. To convert a percentage to a decimal, you simply divide the percentage by 100. This is because 'percent' literally means 'per hundred.'
For instance, if you start with 99%, you divide 99 by 100. This simple calculation converts the percentage to a decimal form:

• 99 divided by 100 equals 0.99

The decimal form is more versatile for mathematical operations such as multiplication or addition. Understanding this conversion is crucial, as many real-world scenarios require working with decimal forms of percentages.

multiplying decimals

Once you have converted a percentage to a decimal, the next step often involves multiplying this decimal by another number. This operation is common when determining how much a percentage of a particular number is. For example, in everyday shopping experiences, people often calculate discounts this way.
When multiplying decimals:

• It is important to align the numbers correctly based on their place values.
• Multiply as if they are regular whole numbers.
• Count the total number of decimal places in both factors.
• Finally, place the decimal in the answer, ensuring it has the same number of places as counted earlier.

In our specific example, multiplying 0.99 by 400 involves first treating it as 99 times 400, yielding 39600. Then, considering that 0.99 has two decimal places, we adjust our product to also have two decimal points. Thus, the final answer is 396.

real-world applications of percentages

Understanding how to work with percentages has a wide range of applications in everyday life. It helps us make sense of situations where parts of a whole need to be understood in relation to the whole. Applications include:

• Shopping: Calculating discounts during sales by converting the percentage discount into a decimal and multiplying it by the price of an item.
• Finance: Interest rates on loans or investments are often expressed as percentages. Understanding how to convert and multiply these can greatly affect your financial planning.
• Statistics: When interpreting data, percentages make it easier to understand proportions.
• Health: In nutrition, knowing the percentage of nutrient content helps in dietary planning.

Mastering the concept of percentages thus enhances decision-making and problem-solving skills in various practical situations.