1. The problem is to add two numbers. 2. The formula for addition is simply $a + b$, where $a$ and $b$ are the two numbers. 3. Addition means combining the values of $a$ and $b$ to get a total. 4. For example, if $a = 3$ and $b = 5$, then the sum is calculated as: $$3 + 5 = 8$$ 5. This means when you add 3 and 5, you get 8. 6. Addition is commutative, meaning $a + b = b + a$. 7. It is also associative, so $(a + b) + c = a + (b + c)$. 8. To add any two numbers, just combine their values using the plus sign $+$.