Transcript Mod 8 Rational and Irrational Numbers (Day 1)

We are learning to…identify rational and irrational
numbers.
Thursday, June 2, 2016

What about 2? Is there a whole number solution?
Why not?

Try the square root of 2 on a calculator…write your
solution.

This is known as an irrational number.
Rational Numbers
Irrational Numbers
2

Irrational Numbers – A number that when written as a decimal does
not end and never repeats.
 An irrational number can never be written as a fraction.

Rational Number – A number that when written as a decimal either
stops or repeats in a pattern.
 All rational numbers can be written as fractions.
1
3

When a decimal repeats in a pattern you can draw a bar above the
repeating part to demonstrate the pattern.
1
 1  3  0.333333333333333  0.3
3
2
 2  7  0.28571428571428 0.285714
7
Try the last two examples with your partners!
•
All of these are examples of rational numbers because…
•
They are written as fractions and decimals that repeat in a pattern.
  3.14159265358979323846264...
2  1.41421356237309504880168...
•These are both examples of irrational numbers because…
•When written as a decimal they will never end, and never repeat in
a pattern.
•Also, these numbers cannot be written as a fraction.
•Every square root of a non-perfect square is an irrational number.