Well as for my 6 year old, she start playing poker when she was 4 years old.  It all started when she started showing the concept of wanting to count.  For instance saying numbers, but not in the correct order, and pattern matching with things like toys, aligning them up in a row, and others.  During this time, she notice me Daddie watching the poker shows and people clapping in the back ground, and the numbers on the tv screen.  So, why not, buy some cards.  Show her how the numbers correspond to how many pictures on the cards.  4 of hearts, 4 large hearts in the middle of the card, don't include the small (baby) hearts next to the numbers.  And the shapes, Hearts, every girl loves hearts.  Diamonds, shiny things on that cartoon Trollz.  Clubs, kinda difficult, but got that shape, and Spades.  Just say Black heart spades.  Notice the spade upside down, showing the ace of spades, looks like a heart with a stem, and point at an apple with a steam.  Then Poker chips, best to get ones with denominations or numbers starting with 1.  We bought $1, $5, $10, $25, $100, $500, $1000, $5000 (pink).  So counting by ones, she learned how to count by 5's, 10's, & 25's up to a hundred.  Then instead of saying "ten hundred" say "one thousand".  So you have the hundred's family, and the thousand's family.  Once she knew about the comma being "thousand" then showing her another comma "million" was a piece of cake.  So shoving in the middle of the table $485 chips looked like a lot, but telling her, it's only 1 $500 chips, the perception of amount dollar wise was easily taught.  Because someone puts in a lot of chips, VALUE WISE, it's pretty small if you have the larger valued chips.  Simple way of showing what is smaller and bigger dealing with numbers.  And she knowing how to shuffle cards too is a plus.  So playing poker for a solid 4 1/2 years with the knowledge of the game is quite awesome if you as me.  The most difficult hand to describe was the STRAIGHT.  Because you have many types to make a straight, open ended, gut shot, double bell buster gut shot, etc.  But a pair, two pair, and three of a kind, and four of a kind, and of course full house (in that order) was easy.  And the easiest, FLUSH.  All same suite.  So when she got a flush, the deal was to "GO FLUSH THE TOILET".  Gotta make the game fun somehow.  Showing Ace, King, Queen, Jack, 10 which one was higher, tape some cards on the wall with the ACE being highest to the ceiling, and then King, Queen, Jack, and 10 being the lowest.  So you ask, which one is HIGHEst to the ceiling?  Well that ACE, then KING.  So you ask, which is HIGHER TO THE CEILING, King or Queen?  Point at the wall.  And as for the Ace being ONE or the Highest card, that was simple.  During a straight with A,2,3,4,5, you look at the numbers and it's just one, the smallest, anything else it's the highest.  It's a "MAGIC CARD" that changes it's mind on a straight hand.