the date of a penny is on the front
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.
1970-S
A penny wirh a small date on it
1928 is a common date for wheat penny's, most show heavy wear and sell for 10 to 50 cents.
...If you can read the date on the penny, it is not an unstamped penny.
Your answer depends on the date on the penny.
1936 is a common date wheat penny, most coins in average condition are valued at 3 to 10 cents
There's a picture at this site:
1941 is a common date, most are valued at 5 to 25 cents.
1941 is a common date, most are valued at 3 to 25 cents.
A very common date "Wheat Cent" most are 3 to 10 cents.