➕pre-algebra review

key term - Decimal

Citation:

Definition

A decimal is a numerical representation that uses a decimal point to express a value that is not a whole number. Decimals allow for the precise expression of quantities and enable the representation of fractional values, which is essential in various mathematical and scientific applications.

5 Must Know Facts For Your Next Test

  1. Decimals allow for the precise representation of values between whole numbers, enabling the expression of more detailed measurements and calculations.
  2. Decimals can be converted to and from fractions, making them useful in simplifying and working with fractional quantities.
  3. Percent is a special type of decimal representation, where the decimal value is multiplied by 100 to express a quantity as a part of 100.
  4. Decimals are essential in solving proportions, as they allow for the precise comparison of ratios and the determination of unknown values.
  5. The placement of the decimal point in a number determines the value of the digits, with each digit to the right of the decimal point representing a smaller fractional value.

Review Questions

  • Explain how decimals can be used to represent and work with fractions.
    • Decimals and fractions are closely related, as decimals can be used to express fractional values. For example, the fraction 3/4 can be represented as the decimal 0.75. This allows for more precise calculations and comparisons involving fractional quantities. Conversely, decimals can be converted to fractions by identifying the place value of the digits and expressing the decimal as a fraction with the appropriate denominator.
  • Describe the role of decimals in understanding and calculating percentages.
    • Decimals are fundamental to the concept of percentages, as a percent is a special type of decimal representation. A percent expresses a quantity as a fraction of 100, with the decimal value multiplied by 100 to represent the percentage. For instance, 0.75 can be expressed as 75%. This relationship between decimals and percentages allows for the easy conversion between the two, which is essential in various applications, such as calculating discounts, interest rates, and other financial calculations.
  • Analyze how decimals are used in solving proportions and their applications.
    • Decimals are crucial in solving proportions, which are statements of equality between two ratios. When working with proportions, the values being compared must be in the same unit, which is often achieved by expressing them as decimals. For example, in a proportion such as 3/4 = x/12, the unknown value x can be solved by cross-multiplying and dividing, resulting in x = 3. This process relies on the ability to accurately represent and manipulate the decimal values in the proportion. Decimals enable the precise comparison of ratios, making them essential in applications like scale drawings, unit conversions, and other problems involving proportional relationships.

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