Understanding of Rational Numbers

are ratios of two integers

if you can convert a number into a fraction it is a rational number

all positive and negative numbers

decimals that terminate or have repeating patterns

Fractions:

Decimals:  $-0.3,\ 2.6,\ or\ 0.\overline{5}$  

Integers: -10, -2, 0, 4, 25

a number multiplied by itself twice

The symbol around the 25 means to square root the number $\sqrt{25\ }\$  

 $\sqrt{25}\ =\ 5$  

 $\sqrt{81}\ =\ 9$  

Cannot be converted into a ratio of two integers

Π (Pi) is irrational

If a number inside the radical is not a perfect square, then it is irrational. 

 $\sqrt{13}$  is irratonal because there is not a number that multiplies by itself to get 13