Addition is simply the process of combining two or more numbers to find their total. Think of it as joining groups of things together. If you have two apples and someone gives you three more, you add them up to see how many you have in total.

To write an addition problem, we use two special symbols. The plus sign ($+$) shows that we are combining numbers. The equals sign ($=$) shows what the total is. So, when we combine two and three, we write it like this:

Addition has a couple of simple rules that make it predictable and easy to work with. The first one is about order. Does it matter which number you start with? Let's say you have 2 oranges and add 3 more. You get 5. What if you started with 3 oranges and added 2 more? You still get 5. The order doesn't change the outcome.

The second rule is about grouping. If you need to add three or more numbers, you can group them in any way you like. Imagine adding 1, 2, and 3. You could add 1 and 2 first to get 3, and then add the final 3 to get 6. Or, you could add 2 and 3 first to get 5, and then add the 1 to get 6. The result is the same.

Sometimes it's helpful to see what addition looks like. A number line is a great tool for this. A number line is just a line with numbers marked at regular intervals. To add, you start at the first number and then move to the right by the amount of the second number.

In the example above, to solve $3+4$, we start at 3 on the number line. Then we move 4 steps to the right, which lands us on 7. This visual method confirms that $3 + 4 = 7$. These basic properties and tools are the foundation for all types of calculations you'll encounter in math.