the date of a penny is on the front
1970-S
A penny wirh a small date on it
The most sought after wheat penny is the 1943 copper penny with only about 12 examples known. These are error coins (all other 1943 cents were struck in steel) and a genuine 1943 copper penny is worth over $100,000. The rarest non-error and regular issue coin is the 1909 S VDB cent which goes for $200 or more depending on the grade.
1928 is a common date for wheat penny's, most show heavy wear and sell for 10 to 50 cents.
The most valuable penny is the 1943 copper penny, which was mistakenly minted in copper instead of the usual zinc-coated steel. One of these rare coins sold for over $1.7 million in a private sale. Other highly valuable pennies include the 1909-S V.D.B. penny and certain 1983 varieties, but the 1943 copper penny remains the most sought after by collectors.
...If you can read the date on the penny, it is not an unstamped penny.
1936 is a common date wheat penny, most coins in average condition are valued at 3 to 10 cents
Your answer depends on the date on the penny.
A very common date "Wheat Cent" most are 3 to 10 cents.
1941 is a common date, most are valued at 3 to 25 cents.
1941 is a common date, most are valued at 5 to 25 cents.