Now have on person grab one magazine binder on one side and a second person grab the other binder on the other side. Now pull horizontally. Do the magazines come apart? If you pull hard enough, yes, but you have to pull very hard. The greater the number of pages, the harder it is to pull apart. My daughters gave it a try and were unsuccessful as you can see in the video below.
We then picked up one magazine and held the bundle vertically to see if gravity could do the trick. No luck.
The friction force between any two pages is small, but add it up over all of the pages and the force is very large. Mythbusters did this once with two phone books and ropes and chains were breaking while the books stayed stuck together, simply from the friction force of paper on paper.
Give it a try, your kids will find it very cool!