ELI5: Explain Like I'm 5

Additive group

Imagine you have a bunch of candies. Let's say you have 3 candies. You can add more candies to your group. If you add 2 more candies, you will end up with 5 candies in your group. This is an example of an additive group.

In mathematics, an additive group is a collection of objects that can be added together. It follows a set of rules that allow you to add and subtract the objects in the group. Examples of additive groups include integers, rational numbers, real numbers, and complex numbers.

In an additive group, you have a few basic operations you can do with the objects in the group. The most basic operation is addition. If you add two objects together, you get a new object in the group. This new object is called the sum of the original objects.

For example, if you have the number 2 and you add it to the number 3, you get the sum of 5. This new number is also in the additive group.

You can also subtract objects in an additive group. If you have the number 10 and you subtract the number 4, you get the difference of 6. This new number is also in the additive group.

Additive groups have some special properties that make them useful in math. One property is the existence of an identity element. This means that there is a special object in the group that, when added to any other object, leaves that object unchanged.

For example, in the additive group of integers, the identity element is the number 0. If you add any integer to 0, you get the same integer back. This property makes it easy to do calculations in the group.

Another property of additive groups is the existence of an inverse element. This means that for every object in the group, there is a corresponding object that, when added to the original object, gives you the identity element.

For example, in the additive group of integers, the inverse element of the number 5 is the number -5. If you add 5 and -5 together, you get the identity element of 0.

Overall, an additive group is a collection of objects that can be added and subtracted together, and that follows a set of rules that make them useful in mathematics. It's like having a bunch of candies that you can add or take away, and there are some special candies that help you do the calculations.