Addition, Subtraction and Multiplication Rules for Even and Odd Numbers

Addition Rules for Even and Odd Numbers
1. Sum of any number of even numbers is always even
2. Sum of even number of odd numbers is always even
3. Sum of odd number of odd numbers is always odd

Subtraction Rules for Even and Odd Numbers
1. Difference of two even numbers is always even
2. Difference of two odd numbers is always even

Multiplication Rules for Even and Odd Numbers
1. Product of even numbers is always even
2. Product of odd numbers is always odd
3. If there is at least one even number multiplied by any number of odd numbers, the product is always even