Rational Numbers

1.5  Rational Numbers
 
  Definition  
     
 

A number that can be written in fractional form \(\dfrac{p}{q}\), where \(p\) and \(q\) are integers and \(q\neq0\).

 
 
  • Examples: \(-\dfrac{1}{2},\, 7.5,\, 4\)
 
Combined basic arithmetic operations of rational numbers:
 
  Example  
     
 

Calculate:

\(\begin{aligned} &\space-0.8+\dfrac{3}{4}\times\bigg(-2\dfrac{1}{6}\bigg) \\\\&=-\dfrac{8}{10}+\dfrac{3}{4}\times\bigg(-\dfrac{13}{6}\bigg) \\\\&=-\dfrac{8}{10}+\bigg(-\dfrac{13}{8}\bigg) \\\\&=-\dfrac{64}{80}-\dfrac{130}{80} \\\\&=-\dfrac{194}{80} \\\\&=-2\dfrac{17}{40}. \end{aligned}\)