diff --git a/apps/calcul/Makefile b/apps/calcul/Makefile
index 866ecd119..d214874fc 100644
--- a/apps/calcul/Makefile
+++ b/apps/calcul/Makefile
@@ -1,6 +1,7 @@
 app_objs += $(addprefix apps/calcul/,\
   app.o\
   calcul_controller.o\
+  calcul.o\
 )
 
 inline_images += apps/calcul/calcul_icon.png
diff --git a/apps/calcul/calcul.cpp b/apps/calcul/calcul.cpp
new file mode 100644
index 000000000..47f5c24bc
--- /dev/null
+++ b/apps/calcul/calcul.cpp
@@ -0,0 +1,55 @@
+#include "calcul.h"
+#include <string.h>
+
+namespace Calcul {
+
+Calcul::Calcul() :
+  m_text("1+3"),
+  m_expression(nullptr),
+  m_layout(nullptr),
+  m_evaluation(Float(3.0f))
+{
+  // TODO: this is temporary. To test the render.
+  m_expression = Expression::parse(m_text);
+  m_layout = expression()->createLayout();
+}
+
+void Calcul::setContent(const char * c, Context * context) {
+  strlcpy(m_text, c, sizeof(m_text));
+  if (m_expression != nullptr) {
+    delete m_expression;
+  }
+  m_expression = Expression::parse(m_text);
+  if (m_layout != nullptr) {
+    delete m_layout;
+  }
+  m_layout = expression()->createLayout();
+  m_evaluation = m_expression->approximate(*context);
+}
+
+Calcul::~Calcul() {
+  if (m_layout != nullptr) {
+    delete m_layout;
+  }
+  if (m_expression != nullptr) {
+    delete m_expression;
+  }
+}
+
+const char * Calcul::text() {
+  return m_text;
+}
+
+Expression * Calcul::expression() {
+  return m_expression;
+}
+
+ExpressionLayout * Calcul::layout() {
+  return m_layout;
+}
+
+Float * Calcul::evaluation() {
+  return &m_evaluation;
+}
+
+}
diff --git a/apps/calcul/calcul.h b/apps/calcul/calcul.h
new file mode 100644
index 000000000..d2defa005
--- /dev/null
+++ b/apps/calcul/calcul.h
@@ -0,0 +1,27 @@
+#ifndef CALCUL_CALCUL_H
+#define CALCUL_CALCUL_H
+
+#include <poincare.h>
+
+namespace Calcul {
+
+class Calcul {
+public:
+  Calcul();
+  ~Calcul(); // Delete expression and layout, if needed
+  const char * text();
+  Expression * expression();
+  ExpressionLayout * layout();
+  Float * evaluation();
+  void setContent(const char * c, Context * context);
+private:
+  constexpr static int k_bodyLength = 255;
+  char m_text[k_bodyLength];
+  Expression * m_expression;
+  ExpressionLayout * m_layout;
+  Float m_evaluation;
+};
+
+}
+
+#endif