J's been obsessed with his piggy bank since a very young age. Under close adult supervision, even kids under 2 can learn to take money in and out of the piggy bank (I'm sure you can find one super cheap at the dollar store). Ours was a shower gift from a friend. Also, we never walk past money on the ground anymore since J is always interested in filling his bank.
*Take the money out of the piggy bank.
*Identify that there are different coins that represent different amounts of money (don't go into too much detail).
*Start counting with the money (count as high as your child has attention span for).
*Put coins back into piggy bank.
*Shake piggy bank - what kind of sound do you hear?
*Is the piggy bank heavy or light?
Older Toddler/Young Preschool age:
*Take out the money from the piggy bank.
*Sort the money into different piles, one for each type of coin.
*Identify the types of coins by name (ie. penny, nickel, dime, quarter).
*Start the conversation that pennies equal 1, nickels equal 5, dimes equal 10 (even if they are the smallest!), and quarters equal 25.
*Count pennies as high as your child can given their attention span.
*See if you can start counting by 5's or 10's (probably not, but worth the try).
*Count coins as your kid puts them back into the piggy bank.
Older Preschool/Early Elementary:
*Sort money into different piles by coin type.
*Count how many of each coin there are.
*Introduce addition: if your child has 3 pennies in his bank and you find 2 pennies (say on the dresser) and add them to his bank, count how many he now has.
*Which is more money: 3 pennies or 7 pennies?
*If 7 pennies are more than 3 (hope I didn't ruin the above bullet), and dimes are actually worth 10 pennies, can you identify with is worth more: 7 pennies or 1 dime?
*Count by 5's for the nickels and see how much money you have in nickels (early multiplication).
*Count by 10's for the dimes and see how much money you have in nickels (early multiplication).
*Have your child divide the pennies into equal piles (I recommend one per person in the house). How many does each person get? (Early division)
*Have a treat that costs 8 cents and see if your child can come up with a combination of coins that equal 8 cents (addition/subtraction). If your child has 11 cents and it cost 8 cents for the treat, how much money does he/she have left? (yay, math word problems aren't really that scary).
*Take your child to a party store, where you can buy little fun, cheap toys with his/her coins. This can show that money actually represents something.
*Consider allowance for chores to add to the wealth.