noun

1. ADDITION, the act of adding one thing to another
2. ADDITION, the arithmetic operation of summing; calculating the sum of two or more numbers
3. ADDITION, a component that is added to something to improve it
4. ADDITION, a suburban area laid out in streets and lots for a future residential area
5. ADDITION, something added to what you already have
6. ADDITION, a quantity that is added
7. ADDITION, the act or process of joining something to something else : the act or process of adding something
8. ADDITION, the act or process of adding numbers
9. ADDITION, something or someone more that is included : something or someone that is added

1. The children learned addition and subtraction.
2. The museum's collection includes several new additions.