G8

(^) Copyright © Swun Math Grade 8 Unit 1 Lesson 2 C TE

Input/Model

(Teacher Presents)

Directions: Determine if the number is rational or irrational. Justify your answer.

Solution:

• The number seventy-
  four hundredths is a
  terminating decimal.
  Therefore, it is
  considered to be a
  rational number.


• It can be re-written as
  the fraction^37
  50
  2. 0.01001000100001...

Solution:

• This is an irrational
  number. I t is a
  decimal that has no
  set pattern and it
  doesn’t terminate.


• You cannot write this
  number as a ratio.

3. (^) √ 7
   Solution:

• I know that the square
  root of seven is an
  irrational number.


• The decimal form of
  this number is
  2.64575131106... it
  never ends and it
  doesn’t have a set
  pattern or repeat.
  4. 휋휋

Solution:

• 휋휋 is an irrational
  number.


• When I punch π on
  the calculator, I get
  the decimal
  3.1415926535...


• This decimal is
  neither terminating
  nor has a set pattern.

Considerations:

• Have conversations with students stating the type of numbers that are considered rational and irrational.


• Create a table or circle map with the center being natural numbers and in the outer circles stating every
  type of number that is considered rational. Give an example for each one.


• Do the same task, but this time with irrational numbers. Give examples of these numbers.


• Draw a rectangle to enclose both and label as “real numbers”.


• When sharing the above information, justify why the numbers are irrational or rational. Add them to the
  circle map/poster you created.

v v

rational

integer

whole

Real Numbers

irrational