The absolute value of a number is the distance from that number to 0 on a number line. When doing absolute value calculations, anything inside the absolute value symbols is positive. |-6| = 6 because -6 is 6 units away from 0 on the number line

The opposite of a number is a negative number if the number is positive and a positive number if the number is negative. The opposite of 6 is -6 and the opposite of -7 is 7.

A prime number is a number that has no other divisors other than itself and 1. 13 is a prime number since nothing can divide 13, except 1 and 13. A composite number is a number that is not prime. 16 is not a prime number, but a composite number since 16 can be divided by 2,4, and 8.

An even number is a number that is divisible by 2. If a number is not divisible by 2, it is odd. 5 is an odd number because 2 does not go into 5. 8 is an even number since 8 ÷ 2 = 4