Unless it's a kids restaurant , my material is always for the parents but if the kids are under 6 I make them laugh (squeeze the food ..) and if they 're 7 to 12 years I make them participate to the tricks as assistant.

My favorite is Al Goshman's sponge bunnies. They are the older ones with short ears. Some years ago Morrissey Magic told me that they were been discontinued. I bought quite a few set to put aside and I'm glad I did. I do find the shorter ears are easier to handle.
Tricky Ricky.

Silk TT routine.

Torn & Restored Cigarette Paper.

My vote goes to sponge balls.

I've posted about this elsewhere but it bears repeating because it's worth performing

I used to do a ballroom-sized walkaround pre-show (meaning the audience was already there for magic and there were lots of kids) with just a SuperSharpie and a Post-It pad

For each kid, I'd write a number and tell them to "throw up fingers." Whatever number they showed, they'd be right!

For a simple effect, it got astounding reactions (astounding to me, that is). The kids "got it" right away, and their reactions delighted their parents too.

Curtis Kam explained it best: kids aren't necessarily impressed by the adult doing magic or reading minds - for all they know, adults just have that power naturally. But the kids know that they, themselves, do NOT have the power to read a grown-up's mind, so they're astonished to be proven right.

That's a lot of mileage to get out of office products (since any SG will do, obviously).