For help finding factors:
Factors are simply the numbers that your multiply together to get another number. For example, in 8 X7 = 56, 8 and 7 are the factors of 56.
To list all of the factors of a number, just list all of the numbers that can be multiplied together to get that number.
Example: The factors for 12 are 1,12, 2,6, and 3 and 4.
https://learnzillion.com/lesson_plans/8409-find-all-the-factor-pairs-of-a-number-using-area-models/
https://learnzillion.com/lesson_plans/6637-find-all-factor-pairs-of-a-number-using-a-t-chart/
Multiples
https://learnzillion.com/lesson_plans/7683-determine-multiples-of-a-number-using-area-models/
https://learnzillion.com/lesson_plans/6626-determine-multiples-of-a-number-using-number-bonds/
https://learnzillion.com/lesson_plans/5408-find-multiples-by-using-a-number-line/
Divisibility Rules
Patterns
https://learnzillion.com/resources/101144-patterns-4th-grade/