This document provides a summary of key concepts from Chapter 4 of a mathematics textbook, including:
1) Rules for determining if a number is divisible by 2, 5, 10, 3, or 9 based on its digits.
2) Exponents represent the number of times a base is used as a factor. Exponents are considered in the order of operations.
3) Prime numbers are only divisible by 1 and themselves, while composite numbers have more than two factors. Factor trees can be used to find the prime factorization of a number.
4) The greatest common factor (GCF) of two or more numbers is the largest factor that is common to all of them. To find the GCF