From the U.S. Mint website:

... a torch signifying Liberty, with an olive branch on the left signifying Peace, and an oak branch on the right, signifying Strength and Independence.

On the back of the dime, there is an olive branch and an oak branch.

The number 52 is represented in Roman numerals by LII - L signifying 50, I signifying 1.

for signs signifying time, most signs signifying the past will move backwards over your shoulder or backwards in comparison with the present time. In the futue, is the opposite, the sign usually moves forward

An octadecagon, also called an octakaidecagon, has 18 sides, from the Greek octa-, signifying 8, the connector -kai-, and deca- signifying 10.