Loyola University Chicago
Math Flix: Prime Numbers: Sieve of Eratosthenes Part 1
This QuickTime movie uses a hundreds chart to record all the prime numbers between 1 and 100 by eliminating all the composite numbers. A pdf worksheet is available by clicking on the hyperlink at the bottom of the page. As you watch and...
Loyola University Chicago
Math Flix: Prime Numbers: Seen in Graphics
This QuickTime movie provides an explanation of just what prime numbers are using graphics. As you watch and listen to the teacher and students interact it helps clarify the thinking behind applying this concept.
Math Antics
Math Antics: Prime Factorization
Gain a basic understanding of prime factorization by watching this easy to understand video tutorial. Additional resources are available as part of a paid subscription service. [6:40]
Khan Academy
Khan Academy: Prime Numbers
Prime numbers are numbers that have only 2 factors: 1 and themselves. For example, the first 5 prime numbers are 2, 3, 5, 7, and 11. By contrast, numbers with more than 2 factors are called composite numbers.
Khan Academy
Khan Academy: Factors and Multiples: Days of the Week
Sal Khan uses factors and multiples to figure out days of the week.
Khan Academy
Khan Academy: Finding Factors and Multiples
Sal Khan uses divisibility rules to determine if numbers are factors of 154 and then finds multiples of 14.
Khan Academy
Khan Academy: Quotients That Are Multiples of 10
Lindsay breaks down division problems using multiples of 10.
Khan Academy
Khan Academy: Recognizing Prime and Composite Numbers
Can you recognize the prime numbers in this group of numbers? Which are prime, composite, or neither?
Khan Academy
Khan Academy: Rounding Whole Numbers: Missing Digit
Lindsay finds the missing digit in an estimation problem by using a number line.
Khan Academy
Khan Academy: Rounding Whole Numbers Word Problems
Sal solves word problems by rounding whole numbers to the nearest ten, hundred, or thousand.
Sophia Learning
Sophia: Divisibility: Lesson 1
This lesson grouping provides students with a wide variety of tricks and techniques to determine if one number is divisible by another number. It is 1 of 6 in the series titled "Divisibility."
Sophia Learning
Sophia: Divisibility: Lesson 2
This lesson grouping provides students with a wide variety of tricks and techniques to determine if one number is divisible by another number. It is 2 of 6 in the series titled "Divisibility."