<< Back to Lessons Index

7th Grade Math / Lesson 2: Decimals: Rational and Irrational

DECIMALS
What will we be learning in this unit?


  • In this lesson you will learn about irrational and rational numbers.

    Vocabulary words are found in this purple color throughout the lesson. Remember to put these in your notebook.


DECIMALS
Converting Fractions to Decimals


To convert a fraction to a decimal you have to do division.

  • Take the numerator and divide it by the denominator.

    65         65 / 32 = 2.03125
    32

  • If the decimal value has an ending, this is a terminating decimal.
    3 = .375
    8
  • If the decimal value has a series of digits that repeat, this is a repeating decimal.
     
                                                         The 2 and 7 repeat.
                       3  = .272727...      = .27      Place a bar above the digits that repeat
                       11
     


  • DECIMALS
    Converting Fractions to Decimals


    To convert a fraction to a decimal you have to do division.
     

  • Take the numerator and divide it by the denominator.

     Decide if the following fractions are terminating, repeating, or neither.

      1. 4/15

      2. 4/17

      3. 4/ 5


  • DECIMALS
    Converting Fractions to Decimals


    To convert a fraction to a decimal you have to do division.
     

  • Take the numerator and divide it by the denominator.

     Decide if the following fractions are terminating, repeating, or neither.

    1.    4             Repeating     ( the 6 repeats )
          15
     
    2.   4             Neither   (the digits keep going and they do not repeat)
         17
     
    3.   4               Terminating  (.8)
          5

  • DECIMALS
    Converting Fractions to Decimals


    Rational numbers are those decimals that DO repeat or terminate.

     Irrational numbers are those decimals that do not repeat and do not terminate.

    For additional practice on rational and irrational numbers, click HERE. To return to this lesson slide, just close the screen by clicking on the x in the top right corner.