Chef Henri is very particular about where he gets the ingredients for his recipes. For instance, for eggs, he will only buy from two specific farmers, Monsieur Egblanc and Monsieur Egbrun. One day, he purchases 4 dozen eggs from M. Egblanc and no eggs from M. Egbrun. How many eggs did Chef Henri buy that day?
Of course, the answer to that is 4 dozen eggs because 4 + 0 = 4.

This illustrates the Additive Identity Property of Zero.

Zero is called the additive identity because adding zero to any number doesn't change that number's value. Therefore, the number keeps its identity.





  On the particular day on which Chef Henri bought the 4 dozen eggs from M. Egblanc, he used 4 dozen eggs to fill orders at his restaurant that night. We can represent the eggs he bought as +4 (positive four) and the eggs he used as -4 (negative four). If he adds these together, he will find that he has no eggs left. 4 + -4 = 0.

This is an example of the
Property of Opposites.

The numbers
4 and -4 are examples of additive inverses or opposites. The additive inverse of
17 is -17,
the additive inverse of
-42 is 42,
and the additive inverse of
-½ is ½. Adding additive inverses will always produce the sum of zero.




Use the Additive Identity Property of Zero and the Property of Opposites to help Chef Henri with this problem:

The following day Chef Henri buys 0 eggs from M. Egblanc and
50 eggs from M. Egbrun. Henri uses 50 eggs in his recipes that evening.

Write an equation which shows how many eggs Henri has left at the end of the day.




Number Theory Main