1.1.3 Even and Odd Numbers
Even Numbers
An even number is a number that can be divided into two equal groups.
Even numbers end in 0, 2, 4, 6, 8.
Odd Numbers
An odd number is a number that cannot be divided into two equal groups.
Odd numbers end in 1, 3, 5, 7, 9.
1.1.4 Prime and Composite Numbers
Prime Numbers
A prime number is a whole number greater than 1 whose only factors are 1 and itself.
Examples: 2, 3, 5, 7, 11, 13, 17, 19
Composite Numbers
Numbers that have more than two factors are called composite numbers.
Why is 1 not a prime number?
1 has only one factor, so it is neither prime nor composite.
Interactive Activity: Classify the Numbers
Click a number. Choose the correct description. Check your answer.