Park Hopper Plus-how Does It Work?

[monita]

HOW DO THE PARK HOPPER PLUS TICKETS WORK ??? FOR EXAMPLE THE PARK HOPPER PLUS 7-DAY TICKET GIVES AN ADDITIONAL 4 PLUS OPTION - ARE THESE 4 ONE-DAY EXTRAS PART OF THE 7 DAYS OR ARE THEY IN ADDITION TO THE 7 DAYS (MAGIC KINGDOM,EPCOT,MGM & ANIMAL KINGDOM) THUS TOTALLING 11 DAYS OF ENTRY?????? WHAT IS THE BEST TICKETS TO BUY, I AM GOING TO BE IN ORLANDO FOR 11 DAYS, HAVE 4 CHILDREN AGES 10,8,5 & 3 (AND A HUSBAND) AND NEED TO SEE ABSOLUTELY EVERYTHING - INCLUDING NASA. (I DON'T WANT TO PAY FOR EXTRA DAYS NOT USED AS THIS TRIP IS COSTING A FORTUNE AND I DON'T EXPECT TO BE BACK).IS THE WEATHER WARM ENOUGH IN MID DECEMBER FOR THE WATER PARKS?? I MAY SEEM A BIT OUT OF TOUCH, BUT I AM TRAVELLING FROM SOUTH AFRICA AND WANT TO BE PREPARED. PLEASE HELP !!!