Actually choking is more common with the very young and the very old - it's related to coordination and teeth! In the very young, choking is common because children are curious and explore by putting everything in their mouth. Small, interesting, shiny objects are likely to attract the child's attention and small children have small airways which are easy to block. And young children, like the very old, typically don't take the time or have the ability to chew food well.

It is most likely that the child WILL throw up afterwards! Stay calm and help the child to stay calm.  Focus on the child - not the vomit or the smell. Help the child clean up and then take the child with you to call the parent. And remember, even though it's not fun to deal with vomit, you saved the child's life and you are a hero!

Remember the difference between coughing and choking.  If the child is coughing, it is better to let them try to cough it out.  Coughing helps!  But if the child is choking, then the child cannot cough, talk, cry, breathe, and will look frightened.  Coughing is "good."  Choking is "bad."  Choking means that the child cannot get rid of the blockage in the airway without help and is a threat to life!  If you rescue a choking child quickly, you won't need to do CPR because you'll get the object out before the child stops breathing.  But without your immediate help, the child could die.

Just make the best decision you can at the time with what you know about the child's size and age. If an infant is a little less than a year old, but is walking and seems large for an infant, it is OK to do abdominal thrusts. The same is true of a small toddler who is just past their first birthday but is small for their age - it is OK to do the back blows/chest thrusts. The most important thing is to make your decision quickly and calmly and then start the steps to rescue the choking child.