The identity element for addition is 0. Any number added to 0 gives you the original number. $$a + 0 = a$$ The identity element for multiplication is 1. Any number multiplied by 1 gives the original number. $$a * 1 = a$$
A general example to help you recognize patterns and spot the information you're looking forAddition: $$10 + 0 = 10$$ Multiplication: $$10 * 0 = 0$$
A mirror is the example of identity property.