\documentclass[12pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[french]{babel}
\usepackage[T1]{fontenc}
\usepackage[margin=1cm]{geometry}
\usepackage{nopageno}
\usepackage{pas-math}
\usepackage{lmodern}
\usepackage{eurosym}
\usepackage{tcolorbox}
	\tcbuselibrary{skins}
	\usetikzlibrary{calc,shapes.geometric,arrows}
\author{Stéphane Pasquet}
\begin{document}
\begin{tcolorbox}[
	title=Calculer le pourcentage d'un nombre,
	fonttitle=\small\bfseries, 
	enhanced jigsaw,
	opacityback=0.5,
	opacitybacktitle=0.75,
	arc=5mm,
	title style={
			left color=green!50!black,
			right color=green!50}]
\[ \dfrac{t}{100} \times \text{ nombre} \]
\textbf{Exemple :} \pourcent{30} de 250 \euro\ = $\dfrac{30}{100}\times250=0,3\times250=75$ \euro.
\end{tcolorbox}

\begin{tcolorbox}[
	title=\'Evolution unique,
	fonttitle=\small\bfseries, 
	enhanced jigsaw,
	opacityback=0.5,
	opacitybacktitle=0.75,
	arc=5mm,
	title style={
			left color=purple!50!black,
			right color=purple!50}]
\begin{center}
\begin{tikzpicture}
\node[ellipse,draw] (A) {Valeur initiale};
\node[ellipse,draw] (B) at ($(A)+(7,0)$) {Valeur finale};
\draw[->,>=stealth',red] (A.north) to[bend left=20] (B.north);
\draw[->,>=stealth',blue] (B.south) to[bend left=20] (A.south);
\node[red] (C) at ($0.5*(A.south)+0.5*(B.south)+(0,2)$) {$\times\left(1\pm\frac{t}{100}\right)$};
\node[blue] at ($0.5*(A.south)+0.5*(B.south)+(0,-1.2)$) {$\div\left(1\pm\frac{t}{100}\right)$};
\node[blue]  (E) at ($0.5*(A.south)+0.5*(B.south)+(0,-2.5)$) {$\times\left(\dfrac{1}{1\pm\frac{t}{100}}\right)$};
\node[blue] at ($0.5*(A.south)+0.5*(B.south)+(-1.5,-1.9)$) {ou};
\node[right] (D) at ($(C)+(4,0)$) {Coefficient Multiplicateur (CM)};
\draw[->,>=stealth'] (D.west) -- (C.east);
\node[right] (F) at ($(E)+(4,0)$) {Coefficient Multiplicateur Réciproque (CMR)};
\draw[->,>=stealth'] (F.west) -- (E.east);
\end{tikzpicture}
\end{center}

\begin{tabular}{@{}ll}
\textbf{Calcul du pourcentage d'évolution :} & $t=\dfrac{\text{Valeur finale}-\text{Valeur initiale}}{\text{Valeur initiale}}\times100$.\\[20pt]
& $t=(CM-1)\times100$.
\end{tabular}
\end{tcolorbox}

\begin{tcolorbox}[
	title=\'Evolutions successives,
	fonttitle=\small\bfseries, 
	enhanced jigsaw,
	opacityback=0.5,
	opacitybacktitle=0.75,
	arc=5mm,
	title style={
			left color=blue!50!black,
			right color=blue!50}]
\begin{center}
\begin{tikzpicture}
\node[ellipse,draw] (A) {$V_1$};
\node[ellipse,draw] (B) at ($(A)+(5,0)$) {$V_2$};
\node[ellipse,draw] (C) at ($(B)+(5,0)$) {$V_3$};
\draw[->,>=stealth',red] (A.north) to[bend left=20] (B.north);
\draw[->,>=stealth',blue] (B.north) to[bend left=20] (C.north);
\node[red] at ($0.5*(A.south)+0.5*(B.south)+(0,2)$) {$\times CM_1$};
\node[blue] at ($0.5*(B.south)+0.5*(C.south)+(0,2)$) {$\times CM_2$};
\draw[->,>=stealth',green!50!black] (A.south) to[bend right=20] (C.south);
\node[green!50!black] at ($0.5*(A.south)+0.5*(C.south)+(0,-1.7)$) {$\times \big(CM_1 \times CM_2\big)$};
\end{tikzpicture}
\end{center}
\end{tcolorbox}
\end{document}