[Soundgod]

Here's my standard breakdown for an adult on the dining plan.

At a sit down meal your appetizer and dessert will both be about $6. Your beverage will be about $2. Your entree will be at least $20. That's $34. Multiply by 1.24 (18% tip and 6% tax is included). That's $42 and change for your sit down meal, which is the only place your DDE card will be accepted, excepting the food courts at the value hotels because they have no table service. Your quick service or counter service meal, usually lunch, gives you a beverage, entree and one side or a platter, and dessert. Figure any platter is at least $7 and as much as $14, dessert $3.50 and beverage $2.50. Minimum is $13, max can be $20 for the chicken and rib platter at Cosmic Ray's. To be fair well use $13 times 1.06 (tax) or almost $14. Snacks can be as much as $4. Your daily adult meal total on meal plan is $60. It's not a bad idea to get the DDE membership if you plan to eat at two table service locations a day or you can do what I do. We're on the dining plan, but have a DDE for the mornings we do character buffets, or any time we do buffets because, especially breakfast, is a waste of a TS credit. Also, you can split your check at the two credit locations and have one person on plan and the other pay out of pocket and sharing appetizer and dessert in order to save credits or even just pay the less expensive meal out of pocket and the more expensive on plan.
I'm sorry I don't have numbers for children, but I'd guess your results will similar, though again, you might benefit from a DDE if the kids want a little more than the standard kid's meal.

If I didn't hit this point before, the DDE gives you a 20% discount on food and beverage, including alcohol, for you and 5 guests in your party. that pretty much covers the tax and tip, or just the tip depending on how you calculate.