Here's some help for winning at candy corn guess raffles.

I used a glass cup to count candy.
Volume of a cylinder: V=height*pi()*radius^2
radius I used: 1.359375 inches
height I used: 5.28125 inches
(glass cup) cylinder volume: 30.65950623

Using this container volume, just divide by the candy's volume to get the count of the container of candy.

Keep track of these values:

For Reese's Pieces, the volume is about 0.0599. The difference on that last decimal place is one little candy piece.
(pedantic info: candy volume for 511 RP candies is 0.05999034. Volume for 512 RP candies is 0.059881848.)

For Brach's normal candy corn, the candy corn volume is 0.158.
(Actual count for my glass cup is 194. These candies have puffed out sides at the bottom.)

STORE BRAND candy corn has a candy corn volume of 0.154 (you can fit a little more in the glass cup, 199 to be exact).
(The store brand candy corn pieces usually have fan shaped striations on both sides.)

So when you're trying to win at those guessing games, you'll have to break down the object into platonic solids and do the volume formula. Then divide by the right candy corn volume number. The result you get is just about the right count for your guess-the-count-raffles.

So that's:
Reese's Pieces: 0.0599
Brach's candy corn: 0.158 (puffy sides)
Store candy corn: 0.154 (with striations)

If they add marbles to throw you off, subtract the volume of the marbles before dividing by your candy volume.

All someone has to do is keep a list of volumes that each type of candy takes up, to help with candy guess raffles.