It is a know fact that you can use wallpaper paste as glue for papier mâché and many people use it for tinkering lanterns etc.
But it is rarely known that you only need a few spoons of flour and water to make a good paper glue.
If you want to make children aware of those carbohydrate based glues, you can also make glue from fresh potatoes.
Mix two spoons of flour with a half cup of cold water. Then add a cup of hot water and heat it carefully (about 5 minutes) until you have a thickish mash. Add a spoon of sugar to preserve it, let it cool down and it is ready for use for example for papier mâché work. Fill it in a screw-top jar and put it in the fridge.
If this takes to much time, you can also mix flour and lukewarm water in proportion 1:1 and wait until it thickens. This glue should be used up instantly.
Grate a peeled potato in a bowl and add three spoons of water. After a few minutes, you can press it with a spoon so the potato starch is on the spoon. Then heat four spoons of the potato starch with four spoons of water until the mass thickens - but don't let it cook! The potato glue dries yellowish and is suitable for paper works.