here is a picture of a 1940 wheat cent. what caused the "9" to look like that and what might it be worth?
Looks to be damage from crimping. This often causes impared mintmarks and digits in dates. Nothing special... Sorry -Brian EDIT: After looking at you included photographs a little bit closer, it looks like whatever is obstructing the '9' is protruding off of the coin. This may be a die chip, but again, this adds no premium to the coins value.
that "obstruction" is the tailend of the "9" there is a blob for lack of better terms where the top of the nine should be I will try to take a better pic
I Beg to Differ. This is a 1940 Cud, a piece of metal distorted the die during pressing and caused the 9 to appear broken or shift and distorted. In 1940 the presses in the Philadelphia mint were inspected in real time by operators. The operator would have caught the error somewhere between 10 and 20 thousand coins produced and stopped the press and isolated the hopper. Depending on the level in the hopper they would have isolated those coins by layer, scooping of the top layer and just sending then to inspection. In 1940 there 586,810,000 pennies minted at the Philadelphia mint, maybe worst case 20,000 got out that makes this coin 1 in 29341 in 1940 and you found it in 2011 makes it about 1 in 208321. I’d say that’s pretty rare. It worth what a collector will pay and there are those who specialize in error coins. If it worth $5.00 that a pretty good jump in value from $0.01
PMD. Coin roller damage. The blob is the remaining displaced material that's left after the rest of the nine was sheared off. Btw.... a "cud" would include the rim otherwise it would be a "die chip" or "die break", which this is not.