diff --git a/poincare/include/poincare/power.h b/poincare/include/poincare/power.h
index 095dfe5cb..04152da80 100644
--- a/poincare/include/poincare/power.h
+++ b/poincare/include/poincare/power.h
@@ -3,6 +3,8 @@
 
 #include <poincare/static_hierarchy.h>
 #include <poincare/evaluation_engine.h>
+#include <poincare/rational.h>
+#include <poincare/multiplication.h>
 
 namespace Poincare {
 
@@ -29,6 +31,12 @@ private:
 
   int compareToGreaterTypeExpression(const Expression * e) const override;
   int compareToSameTypeExpression(const Expression * e) const override;
+  /* Simplification */
+  void immediateSimplify() override;
+  void simplifyRationalPower(Expression * e, Rational * b);
+  void simplifyPowerPower(Power * p, Rational * r);
+  void simplifyPowerMultiplication(Multiplication * m, Rational * r);
+  void simplifyRationalRationalPower(Rational * a, Rational * b);
 };
 
 }
diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index 9ad16bfa9..c94aa6279 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -6,9 +6,8 @@ extern "C" {
 #include <math.h>
 #include <poincare/complex_matrix.h>
 #include <poincare/power.h>
-#include <poincare/multiplication.h>
-#include <poincare/integer.h>
 #include <poincare/opposite.h>
+#include <poincare/undefined.h>
 #include "layout/baseline_relative_layout.h"
 
 namespace Poincare {
@@ -103,4 +102,96 @@ int Power::compareToGreaterTypeExpression(const Expression * e) const {
   return operand(1)->compareTo(&one);
 }
 
+void Power::immediateSimplify() {
+  if (operand(0)->type() == Type::Undefined || operand(1)->type() == Type::Undefined) {
+    replaceWith(new Undefined(), true);
+    return;
+  }
+  if (operand(0)->type() == Type::Rational) {
+    const Rational * a = static_cast<const Rational *>(operand(0));
+    if (a->isZero()) {
+      if (operand(1)->type() == Type::Rational) {
+        const Rational * b = static_cast<const Rational *>(operand(1));
+        if (!b->isNegative()) {
+          replaceWith(new Rational(Integer(0)), true);
+          return;
+        } else {
+          replaceWith(new Undefined(), true);
+          return;
+        }
+      }
+    }
+    if (a->isOne()) {
+      replaceWith(new Rational(Integer(1)), true);
+    }
+  }
+  if (operand(1)->type() == Type::Rational) {
+    const Rational * b = static_cast<const Rational *>(operand(1));
+    simplifyRationalPower(const_cast<Expression *>(operand(0)), const_cast<Rational *>(b));
+  }
+}
+
+void Power::simplifyRationalPower(Expression * e, Rational * b) {
+  if (b->isZero()) {
+    replaceWith(new Rational(Integer(0)), true);
+    return;
+  }
+  if (b->isOne()) {
+    replaceWith(new Rational(Integer(1), true));
+    return;
+  }
+  /* a^n with n Integer */
+  if (b->denominator().isOne()) {
+    if (e->type() == Type::Rational) {
+      Rational r = Rational::Power(*(static_cast<Rational *>(e)), b->numerator());
+      replaceWith(new Rational(r),true);
+      return;
+    } else if (e->type() == Type::Power) {
+      return simplifyPowerPower(static_cast<Power *>(e), b);
+    } else if (e->type() == Type::Multiplication) {
+      return simplifyPowerMultiplication(static_cast<Multiplication *>(e), b);
+    }
+  }
+  if (e->type() == Type::Rational) {
+    return simplifyRationalRationalPower(static_cast<Rational *>((Expression *)operand(0)), b);
+  }
+}
+
+void Power::simplifyPowerPower(Power * p, Rational * r) {
+  const Expression * multOperands[2] = {const_cast<Expression *>(p->operand(1)), r};
+  Multiplication * m = new Multiplication(multOperands, 2, false);
+  replaceOperand(r, m, false);
+  m->immediateSimplify();
+  if (operand(1)->type() == Type::Rational) {
+    simplifyRationalPower(const_cast<Expression *>(operand(0)), static_cast<Rational *>((Expression *)operand(1)));
+  }
+}
+
+void Power::simplifyPowerMultiplication(Multiplication * m, Rational * r) {
+  for (int index = 0; index < m->numberOfOperands(); index++) {
+    Expression * rCopy = r->clone();
+    Expression * factor = const_cast<Expression *>(m->operand(index));
+    const Expression * powOperands[2] = {factor, rCopy};
+    Power * p = new Power(powOperands, false);
+    m->replaceOperand(factor, p, false);
+    p->simplifyRationalPower(const_cast<Expression *>(p->operand(0)), static_cast<Rational *>(rCopy));
+  }
+  detachOperand(m);
+  replaceWith(m, true); // delete r
+  m->immediateSimplify();
+}
+
+void Power::simplifyRationalRationalPower(Rational * a, Rational * b) {
+  /*const Expression * n = SimplifyIntegerRationalPower(a->numerator(), b);
+  const Expression * d = SimplifyIntegerRationalPower(a->denominator(), b);
+  const Expression * multOp[2] = {n, d};
+  Multiplication * m = new Multiplication(multOp, 2, false);
+  replaceWith(m, true);
+  m->immediateSimplify();*/
+}
+
+/*Expression * Power::SimplifyIntegerRationalPower(Integer i, Rational * r) {
+// TODO
+}*/
+
 }