This one is easy, quick and free.
The World Food Programme has an anonymous donor that will feed a child every time someone takes a 5 question quiz about hunger.
The questions and answers are informative without being overly informative (meaning there are no death statistics or anything of that nature) so it would be PERFECT to do with a child. It talks about where the most hungry people are, costs of feeding a child, and things like that. Perfect introductory information…and while you take it you are doing something about it. Pretty cool
At the end you can share it and for each person you share it with another child is fed…which will also make your child an advocate which is a pretty cool thing to explain to them.
It literally took me 45 seconds max. Also, I got 3 out of 5 wrong which is super embarrassing.