There are many easy principles that we all take for granted that you can use to amaze and delight your kids. All you have to do is make the time to spend with them.
These tricks are relatively fast and very simple to execute. The pay-off in looks of wonderment and excitement in you kids' faces will be well worth the time it takes to pull them off.
So plan to turn off the X-Box, PS 2 or 3, Wii or TV, and spend a few minutes with your kids as you introduce them to the wonderful world of mad science experiments.
The tin can phone
The first and easiest thing to do with younger/ toddler kids is the old school string and can phone. All you need for this is 2 empty soup cans, plastic cups, or empty plastic soda/ water bottles cut in half and a length of string, fishing line, etc. Step one is to make a hole in the bottom of your "receivers".
For metal cans I would recommend using a small drill (1/16" or smaller diameter). For the plastic cups or 1/2 bottles you can usually punch a hole in the bottom with an awl or nail. Next feed the line through the two holes and tie knots in the ends large enough to prevent it from pulling through when under tension. If you managed to make too large a hole to be able to tie off the line, tie the line to a METAL washer instead to keep the line from pulling through.
Hand one end to your child, and then pull the line taut. Talk into the can while the child holds the other end to their ear. Switch positions and let your child talk to you through the phone. Don't forget to show them what happens when the line is slack! Although, if yours is like mine, having the line go slack won't be as big a challenge as keeping it taut!
Fun in the sink
Another quick trick that will amaze your kids needs just a sink full of water, 2 mixing bowls, and their favorite small toy. Fill the sink 3/4 full with water. Now bet your kids that you can put their toy into the sink all the way to the bottom while it is full of water with out getting the toy wet.
After the "No way!" "Yes way" fight dies down, put the toy into the smallest mixing bowl you have. then float the bowl in the sink. Put the toy into the bowl. Turn the larger mixing bowl over and use it to force the smaller bowl with the toy to the bottom of the sink. Let your kid's eyes get to their maximum size, and then slowly let the bowls surface.
Remove the large bowl and show them the dry toy. Next see if they can duplicate the feat. Chances are they will get all excited and twitchy and get the toy wet either when they sink it or when they raise it. Make sure you don't use anything electronic as a safety precaution.
Make water flow up hill
The last little bit of hocus pocus also uses the sink, a couple of mixing bowls, a cup, and a hand or kitchen towel. First fill a mixing bowl with water. Then place it on top of another mixing bowl that you have over turned in one side of the sink. Ask your child if they can figure out a way to get the water to run up the side of the mixing bowl, over the divider in the sink and into the cup.
When they either give up or say it is impossible you pull out the towel. Thoroughly wet the towel in the mixing bowl, and then drape it from the bowl, over the divider, and into the cup. Let it stand for a while (ice cream is always a good time killer), now show them that the water has indeed flowed over to the cup and is filling it up. Tell them that they can go to school the next day and tell kids that they can make water flow up hill!
Getting the child's buy in is HUGE in these kid friendly little experiments. Challenging them with what they think is nutty or impossible to do gets their attention and gets them excited to try to prove mom or dad wrong. It also will spread to their friends as they try to duplicate these tricks for them. Just be on the look out for over the top bets on whether or not these tricks can be pulled off successfully. No one wins when someone has to eat a hand full of dirt because of a bet. Yes. I am still a little bitter about that one. Dang older brother! He should have let me off!