Complex Count in \foreach for number line

There are many ways for numerical calculations. The following example uses e-TeX's \numexpr:

\the\numexpr 135 + 5 * \x \relax

Full example:

\documentclass[letterpaper,12pt]{book}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[line width=1pt,line cap=round,x=.5cm,y=.5cm]
  \clip (0,-0.8) rectangle (10,1);
  %   Inequality Line
  \draw   [<->,thick]     (0,0) -- (10,0);
  %   Tick Marks
  \foreach \x in {1,2,...,9}
  \draw (\x,-2pt) -- (\x,2pt) node [anchor=north,below=3pt]
  {$\scriptstyle \the\numexpr135+5*\x\relax$};
  %   Displayed Solution
\end{tikzpicture}
\end{document}

There are many ways for numerical calculations inside \foreach loop. Here are two possibilities, one use count, the other evaluate :

\documentclass[preview, border=7mm]{standalone}
\usepackage{tikz}
\begin{document}
  \begin{tikzpicture}[line width=1pt,line cap=round,x=.5cm,y=.5cm]
    % axes
    \draw   [<->,thick]     (0,0) -- (10,0);
    % tick marks and numbers below
    \foreach[count=\x] \l in {140,145,...,180}
      \draw (\x,2pt) -- (\x,-2pt) node[blue, below,scale=.5]{$\l$};
    % numbers above
    \foreach[evaluate={\l=int(5*\x+135)}] \x in {1,...,9}
      \node[above,scale=.5,red] at (\x,2pt) {$\l$};
  \end{tikzpicture}
\end{document}