Fractions and recurring decimals

Fractions and recurring decimals

Understanding Fractions

  • A fraction represents a part of a whole and consists of a numerator and a denominator.
  • The numerator is the number above the line and indicates the number of considered parts.
  • The denominator is the number below the line and shows the total number of equal parts.
  • For example, in the fraction 3/4, 3 is the numerator which signifies that we’re looking at 3 parts, and 4 is the denominator meaning a whole is divided into 4 equal parts.

Simplifying Fractions

  • A simplified fraction is when the numerator and the denominator have no common factors apart from 1. For example, the fraction 2/4 is not simplified as 2 is a common factor, after simplifying we get 1/2.
  • Remember, the fraction value stays the same when you simplify, you’re just expressing it in the most reduced terms.

Recurring Decimals

  • Recurring decimals are decimals that have digits or groupings of digits that repeat endlessly.
  • Recurring decimals can be written using a dot above the repeating digit (or digits), for example, 0.666… can be written as 0.6̅.
  • Some fractions, when converted into decimal form, give recurring decimals. For example, 1/3 = 0.333…

Converting between Fractions and Recurring Decimals

  • To convert a fraction to a decimal, divide the numerator by the denominator. If the division ends with a remainder, the decimal is finite. If the division leads to an endlessly repeating pattern, the decimal is recurring.
  • Converting a recurring decimal to a fraction requires a more complex process. For a simple recurring decimal like 0.3̅, you would equate it to a variable, multiply it to eliminate the recurrence, and solve for the variable.

Practice Problems

  • Problem: Simplify the fraction 72/90.
    • Solution: Both numbers are divisible by 18, so after dividing both the numerator and denominator by 18, we get 4/5.
  • Problem: Convert the fraction 2/5 to a decimal.
    • Solution: When we divide 2 by 5, we get 0.4.
  • Problem: Convert the recurring decimal 0.777… to a fraction.
    • Solution: Let the variable x equal 0.777… Now, multiply x by 10 to get 10x = 7.777…, then subtract x from 10x to get 9x = 7. Solving for x gives x = 7/9.

Making Sure You Got It

  • Double-check your calculations when working with fractions and recurring decimals.
  • Converting between fractions and recurring decimals or simplifying fractions is easier when you have a strong understanding of division and multiplication.
  • Remember to be aware of repeating patterns and how they affect your outcome when working with recurring decimals.