diff --git a/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/GUI.py b/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/GUI.py
index b223df4ed..6b39ae88b 100644
--- a/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/GUI.py
+++ b/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/GUI.py
@@ -17,7 +17,6 @@ class GUI(ThreadingGUI):
 
     def __init__(self, host="ws://127.0.0.1:2303"):
         super().__init__(host)
-
         self.array = None
         self.array_lock = threading.Lock()
         self.mapXY = None
@@ -42,8 +41,7 @@ def gui_in_thread(self, ws, message):
             data = eval(message[4:])
             self.mapXY = data
             x, y = self.mapXY
-            worldx, worldy = self.map.gridToWorld(x, y)
-            self.worldXY = [worldx, worldy]
+            self.worldXY = self.map.gridToWorld(x, y)
             print(f"World : {self.worldXY}")
 
     # Prepares and sends a map to the websocket server
@@ -97,15 +95,18 @@ def showPath(self, array):
 
     def getTargetPose(self):
         if self.worldXY is not None:
-            return [self.worldXY[1], self.worldXY[0]]
+            return self.worldXY
         else:
             return None
 
     def getMap(self, url):
         return self.map.getMap(url)
     
-    def rowColumn(self, pose):
-        return self.map.rowColumn(pose)
+    def worldToGrid(self, pose):
+        return self.map.worldToGrid(*pose)
+
+    def gridToWorld(self, cell):
+        return self.map.gridToWorld(*cell)
 
     def reset_gui(self):
         """Resets the GUI to its initial state."""
@@ -137,4 +138,11 @@ def getMap(url):
     return gui.getMap(url)
 
 def rowColumn(pose):
-    return gui.rowColumn(pose)
\ No newline at end of file
+    # Deprecated. Still alive for backward compatibility.
+    return list(gui.worldToGrid(pose))
+
+def worldToGrid(pose):
+    return gui.worldToGrid(pose)
+
+def gridToWorld(cell):
+    return gui.gridToWorld(cell)
diff --git a/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/map.py b/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/map.py
index 45adeff0c..4eb084f4b 100644
--- a/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/map.py
+++ b/exercises/static/exercises/global_navigation_newmanager/python_template/ros2_humble/map.py
@@ -6,11 +6,13 @@
 
 class Map:
 	def __init__(self, pose3d):
+		# The world scenario is placed on 0,0. It has a size of 500x500
+		# The coordinates of the map are from 0 to 400, being 0,0 the top left corner
 		self.pose3d = pose3d
 		self.worldWidth = 500
 		self.worldHeight = 500
-		self.gridWidth = 450
-		self.gridHeight = 440
+		self.gridWidth = 400
+		self.gridHeight = 400
 		self.grid = np.empty([self.gridWidth, self.gridHeight], float)
 	
 	def RTx(self, angle, tx, ty, tz):
@@ -39,25 +41,19 @@ def RTGridWorld(self):
 		return RTz*RTx
 
 	def worldToGrid(self, worldX, worldY):
-		# self.gWidth/self.wWidth is the scale
-		worldX = worldX * self.gridWidth/self.worldWidth
-		worldY = worldY * self.gridHeight/self.worldHeight
-		orig_poses = np.matrix([[worldX], [worldY], [0], [1]])
-		final_poses = self.RTWorldGrid() * orig_poses
-		gridX = int(final_poses.flat[0])
-		gridY = int(final_poses.flat[1])
+		""" Transform a world point to map cell coordinates """
+		gridX = (worldY + self.worldHeight/2) * self.gridHeight / self.worldHeight
+		gridY = (worldX + self.worldWidth/2) * self.gridWidth / self.worldWidth
+		gridX = int(np.clip(gridX, 0, self.gridWidth))
+		gridY = int(np.clip(gridY, 0, self.gridHeight))
 		return (gridX, gridY)
 
 	def gridToWorld(self, gridX, gridY):
-		# self.wWidth/self.gWidth is the scale
-		gridX = gridX / 400
-		gridX = gridX * 500
-		worldX = gridX - 250
-		gridY = gridY / 400
-		gridY = gridY * 500
-		worldY = gridY - 250		
+		""" Transform a map cell to world coordinates """
+		worldX = gridY * self.worldHeight / self.gridHeight - self.worldHeight/2
+		worldY = gridX * self.worldWidth / self.gridWidth - self.worldWidth/2
 		return (worldX, worldY)
-		
+
 	def RTFormula(self):
 		RTz = self.RTz(pi/2, 50, 70, 0)
 		return RTz
@@ -68,26 +64,14 @@ def getGridVal(self, x, y):
 
 	def setGridVal(self, x, y, val):
 		self.grid[y][x] = val
-		
+
 	def getTaxiCoordinates(self):
-		
+		""" Return the taxi pose in map coordinates """
 		pose = self.pose3d()
-		x = pose.x
-		y = pose.y
-		#print("x : {} , y : {}".format(x,y))
-		# Transform from world coordinates to map coordinates
-		# The scenario is placed on 0,0. It has a length of 500x500
-		# The coordinates of the map are from 0 to 400, being 0,0 the top left corner
-		x = x + 250
-		x = x / 500
-		x = x * 400
-		y = y + 250
-		y = y / 500
-		y = y * 400
-		#print("x : {} , y : {}".format(x,y))
-		return y, x
+		return self.worldToGrid(pose.x, pose.y)
 
 	def rowColumn(self, pose):
+		# Deprecated. Use worldToGrid()
 		x = pose[0]
 		y = pose[1]
 		#print("x : {} , y : {}".format(x,y))