diff --git a/poincare/include/poincare/grid_layout_node.h b/poincare/include/poincare/grid_layout_node.h
index db0ba9a69..956f5ba49 100644
--- a/poincare/include/poincare/grid_layout_node.h
+++ b/poincare/include/poincare/grid_layout_node.h
@@ -17,12 +17,14 @@ class GridLayoutNode : public LayoutNode {
 public:
   GridLayoutNode() :
     LayoutNode(),
+    m_numberOfChildren(0),
     m_numberOfRows(0),
     m_numberOfColumns(0)
   {}
 
   void setNumberOfRows(int numberOfRows) { m_numberOfRows = numberOfRows; }
   void setNumberOfColumns(int numberOfColumns) { m_numberOfColumns = numberOfColumns; }
+  KDSize gridSize() const { return KDSize(width(), height()); }
 
   // LayoutNode
   void moveCursorLeft(LayoutCursor * cursor, bool * shouldRecomputeLayout) override;
@@ -38,8 +40,20 @@ public:
 
   // TreeNode
   size_t size() const override { return sizeof(GridLayoutNode); }
-  int numberOfChildren() const override { return m_numberOfRows * m_numberOfColumns; }
+  int numberOfChildren() const override { return m_numberOfChildren; }
+  void incrementNumberOfChildren(int increment = 1) override {
+    assert(increment >= 0);
+    m_numberOfChildren += increment;
+  }
+  void decrementNumberOfChildren(int decrement = 1) override {
+    m_numberOfChildren -= decrement;
+    if (m_numberOfChildren < 0) {
+      m_numberOfChildren = 0;
+    }
+  }
+
   void eraseNumberOfChildren() override {
+    m_numberOfChildren = 0;
     m_numberOfRows = 0;
     m_numberOfColumns = 0;
   }
@@ -62,6 +76,7 @@ protected:
   int rowAtChildIndex(int index) const;
   int columnAtChildIndex(int index) const;
   int indexAtRowColumn(int rowIndex, int columnIndex) const;
+  int m_numberOfChildren;
   int m_numberOfRows;
   int m_numberOfColumns;
 
diff --git a/poincare/src/grid_layout_node.cpp b/poincare/src/grid_layout_node.cpp
index f55612979..9f011d295 100644
--- a/poincare/src/grid_layout_node.cpp
+++ b/poincare/src/grid_layout_node.cpp
@@ -162,7 +162,7 @@ int GridLayoutNode::indexAtRowColumn(int rowIndex, int columnIndex) const {
 }
 
 void GridLayoutNode::computeSize() {
-  m_frame.setSize(KDSize(width(), height()));
+  m_frame.setSize(gridSize());
   m_sized = true;
 }