Addition is simply joining or "adding" values, objects or any other things together. For example if I have one apple and I get another apple, now I have added 1 apple to another to create 2 apples. If I simply just have the number 1, and add it to 1, then now I also have the number 2.

Counting Up
Addition Table
Adding to 10
Collumn Addition

Subtraction is the opposite of addition, instead of joining objects, values or other things, you remove a certain amount of objects, values or other things from another amount of objects, values or other things. For example if I have 2 apples but I take away 1, now I only have 1 apple. If I have the number 2 and take away 1 then I have 1

Counting Down
Subtraction Table
Borrowing