[Tex/LaTex] How to reduce the size of fractions typed in align environment

Question

When digit fractions align environment, this goes with a size \displaystyle. But I want the size is like the one shown in a paragraph. I tried with \scriptstyle but I get letters too small and the \small command not working under align environment.
What I can do? Here I put a screenshot, lines down, to further clarify this idea and my question.
Thanks in advance.

\documentclass{article}
\usepackage{showframe}
\usepackage{mathtools,amsmath}
\usepackage{amsthm}
\begin{document}

\begin{align*}
\rightarrow \quad &x=3,\frac{10}{3},\frac{11}{3}.   \tag{1}\\
\end{align*}
This is a text in paragraph: $\textrm{C.S}=\{3,\frac{10}{3},\frac{11}{3}.\}$

\end{document} 

Answer 1

There is another solution if you find there figures in textstyle too small: the \mfrac command,defined in the nccmath package:

\documentclass[12pt, a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{mathtools, nccmath, textcomp} 

\begin{document}

Here’s an align environment typeset first with \verb+\mfrac+, then  \verb+\tfrac+ 
and finally\verb+\mfrac+: 
   \begin{align*}
   \rightarrow \quad &x=3, \frac{10}{3},\frac{11}{3}.  \\
   \rightarrow \quad &x=3, \tfrac{10}{3},\tfrac{11}{3}. \\
   \rightarrow \quad &x=3, \mfrac{10}{3},\mfrac{11}{3}. \\
   \end{align*}

This is a text in paragraph typeset with \verb+\tfrac+: $\textrm{C.S}=\{3,\frac{10}{3},\frac{11}{3}\}$.  

This is a text in another paragraph typeset with \verb+\mfrac+: $\textrm{C.S}=\bigl \{3,\mfrac{10}{3},\mfrac{11}{3}\bigr\}$. 
\end{document}