If you are alone at home and find that you are unable to eat following some piece of food stuck in your mouth then you should try to find a table or a chair and strike your stomach against it. That can be repeated until the food piece comes out and breathing restarts. You can also make fists of your hands on the stomach and fall to the floor. Usually you cannot breath.
In some children who have taken a sticky candy the usual maneuver may not get the candy easily out as it is sticky , so you have to turn the person upside down and jerk them up and down and maybe hit on the back to get the sticky candy loose.
If you see a person seated next to you suddenly stops talking and turns blue, you know that the person is not breathing. Then jump and stand on his back, give a bear hug around him with your fists against his stomach , just below the ribs. Then pull the stomach back with all your force and the blockage will be removed.
If the person is on the floor then you can push against his stomach to try to get the object out of his mouth.
In children thumping their back while they are held upside down will help get the stuck object out.