diff --git a/poincare/Makefile b/poincare/Makefile
index 2c76c3b86..1c0a3dca1 100644
--- a/poincare/Makefile
+++ b/poincare/Makefile
@@ -1,6 +1,7 @@
 SFLAGS += -Ipoincare/include
 objs += $(addprefix poincare/src/,\
   addition.o\
+  commutative_operation.o\
   context.o\
   expression.o\
   float.o\
diff --git a/poincare/include/poincare/addition.h b/poincare/include/poincare/addition.h
index e97d49f48..6eb1c9577 100644
--- a/poincare/include/poincare/addition.h
+++ b/poincare/include/poincare/addition.h
@@ -1,18 +1,14 @@
 #ifndef POINCARE_ADDITION_H
 #define POINCARE_ADDITION_H
 
-#include <poincare/expression.h>
+#include <poincare/commutative_operation.h>
 
-class Addition : public Expression {
+class Addition : public CommutativeOperation {
+  using CommutativeOperation::CommutativeOperation;
   public:
-    Addition(Expression * first_operand, Expression * second_operand);
-    ~Addition();
     ExpressionLayout * createLayout(ExpressionLayout * parent) override;
-    float approximate(Context& context) override;
     Type type() override;
-  private:
-    Expression * m_left;
-    Expression * m_right;
+    float operateApproximatevelyOn(float a, float b) override;
 };
 
 #endif
diff --git a/poincare/include/poincare/commutative_operation.h b/poincare/include/poincare/commutative_operation.h
new file mode 100644
index 000000000..563ff3e18
--- /dev/null
+++ b/poincare/include/poincare/commutative_operation.h
@@ -0,0 +1,20 @@
+#ifndef POINCARE_COMMUTATIVE_OPERATION_H
+#define POINCARE_COMMUTATIVE_OPERATION_H
+
+#include <poincare/expression.h>
+
+class CommutativeOperation : public Expression {
+  public:
+    CommutativeOperation(Expression * first_operand, Expression * second_operand);
+    ~CommutativeOperation();
+    Expression * operand(int i);
+    int numberOfOperands();
+    float approximate(Context& context) override;
+  protected:
+    virtual float operateApproximatevelyOn(float a, float b) = 0;
+  private:
+    int m_numberOfOperands;
+    Expression ** m_operands;
+};
+
+#endif
diff --git a/poincare/include/poincare/product.h b/poincare/include/poincare/product.h
index 557497256..76f3c192c 100644
--- a/poincare/include/poincare/product.h
+++ b/poincare/include/poincare/product.h
@@ -1,21 +1,14 @@
 #ifndef POINCARE_PRODUCT_H
 #define POINCARE_PRODUCT_H
 
-#include <poincare/expression.h>
+#include <poincare/commutative_operation.h>
 
-class Product : public Expression {
+class Product : public CommutativeOperation {
+  using CommutativeOperation::CommutativeOperation;
   public:
-    Product(Expression * first_factor, Expression * second_factor);
-    ~Product();
     ExpressionLayout * createLayout(ExpressionLayout * parent) override;
-    float approximate(Context& context) override;
     Type type() override;
-
-    Expression * factor(int i);
-    int numberOfFactors();
-  private:
-    int m_numberOfFactors;
-    Expression ** m_factors;
+    float operateApproximatevelyOn(float a, float b) override;
 };
 
 #endif
diff --git a/poincare/src/addition.cpp b/poincare/src/addition.cpp
index 9742df74b..beed55a95 100644
--- a/poincare/src/addition.cpp
+++ b/poincare/src/addition.cpp
@@ -1,24 +1,15 @@
 #include <poincare/addition.h>
 #include "layout/horizontal_layout.h"
 
-Addition::Addition(Expression * first_operand, Expression * second_operand) {
-  m_left = first_operand;
-  m_right = second_operand;
-}
-
 Expression::Type Addition::type() {
   return Expression::Type::Addition;
 }
 
-Addition::~Addition() {
-  delete m_left;
-  delete m_right;
-}
-
-float Addition::approximate(Context& context) {
-  return m_left->approximate(context) + m_right->approximate(context);
+float Addition::operateApproximatevelyOn(float a, float b) {
+  return a + b;
 }
 
 ExpressionLayout * Addition::createLayout(ExpressionLayout * parent) {
-  return new HorizontalLayout(parent, m_left, '+', m_right);
+  //FIXME: There can be more than two operands now! :-)
+  return new HorizontalLayout(parent, operand(0), '+', operand(1));
 }
diff --git a/poincare/src/commutative_operation.cpp b/poincare/src/commutative_operation.cpp
new file mode 100644
index 000000000..e61a3c078
--- /dev/null
+++ b/poincare/src/commutative_operation.cpp
@@ -0,0 +1,35 @@
+#include <poincare/commutative_operation.h>
+extern "C" {
+#include <stdlib.h>
+}
+
+CommutativeOperation::CommutativeOperation(Expression * first_operand, Expression * second_operand) {
+  m_numberOfOperands = 2;
+  m_operands = (Expression **)malloc(2*sizeof(Expression *));
+  m_operands[0] = first_operand;
+  m_operands[1] = second_operand;
+}
+
+CommutativeOperation::~CommutativeOperation() {
+  for (int i=0; i<m_numberOfOperands; i++) {
+    delete m_operands[i];
+  }
+  free(m_operands);
+}
+
+int CommutativeOperation::numberOfOperands() {
+  return m_numberOfOperands;
+}
+
+Expression * CommutativeOperation::operand(int i) {
+  return m_operands[i];
+}
+
+float CommutativeOperation::approximate(Context& context) {
+  float result = m_operands[0]->approximate(context);
+  for (size_t i=1; i<m_numberOfOperands; i++) {
+    float next = m_operands[i]->approximate(context);
+    result = this->operateApproximatevelyOn(result, next);
+  }
+  return result;
+}
diff --git a/poincare/src/product.cpp b/poincare/src/product.cpp
index e8b262939..4635fe7ca 100644
--- a/poincare/src/product.cpp
+++ b/poincare/src/product.cpp
@@ -4,33 +4,8 @@ extern "C" {
 #include <stdlib.h>
 }
 
-Product::Product(Expression * first_factor, Expression * second_factor) {
-  m_numberOfFactors = 2;
-  m_factors = (Expression **)malloc(2*sizeof(Expression *));
-  m_factors[0] = first_factor;
-  m_factors[1] = second_factor;
-}
-
-Product::~Product() {
-  for (int i=0; i<m_numberOfFactors; i++) {
-    delete m_factors[i];
-  }
-}
-
-float Product::approximate(Context& context) {
-  float result = m_factors[0]->approximate(context);
-  for (size_t i=1; i<m_numberOfFactors; i++) {
-    result *= m_factors[i]->approximate(context);
-  }
-  return result;
-}
-
-int Product::numberOfFactors() {
-  return m_numberOfFactors;
-}
-
-Expression * Product::factor(int i) {
-  return m_factors[i];
+float Product::operateApproximatevelyOn(float a, float b) {
+  return a*b;
 }
 
 Expression::Type Product::type() {
@@ -39,5 +14,5 @@ Expression::Type Product::type() {
 
 ExpressionLayout * Product::createLayout(ExpressionLayout * parent) {
   //FIXME: There can be more than two factors now! :-)
-  return new HorizontalLayout(parent, m_factors[0], '*', m_factors[1]);
+  return new HorizontalLayout(parent, operand(0), '*', operand(1));
 }
diff --git a/poincare/src/simplify/simplify_product_zero.cpp b/poincare/src/simplify/simplify_product_zero.cpp
index 38e253237..e8e5fef27 100644
--- a/poincare/src/simplify/simplify_product_zero.cpp
+++ b/poincare/src/simplify/simplify_product_zero.cpp
@@ -7,8 +7,8 @@ Expression * SimplifyProductZero(Expression * e) {
     return nullptr;
   }
   Product * p = (Product *)e;
-  for (int i=0; i<p->numberOfFactors(); i++) {
-    Expression * factor = p->factor(i);
+  for (int i=0; i<p->numberOfOperands(); i++) {
+    Expression * factor = p->operand(i);
     if (factor->type() == Expression::Type::Integer) {
       Integer * integer = (Integer *)factor;
       if (*integer == Integer((native_int_t)0)) {