Khan Academy: Computational Number Theory: Algorithmic Efficiency

This video on changing improper fractions to mixed numbers would nicely compliment the Khan Academy video on writing mixed numbers as improper fractions. Sal first shows students how to convert improper fractions. Then, he uses drawings...

Understanding place value is a basic mathematics skill. This Khan Academy video shows students how to write the number 14,897 in the expanded form. He explains that the 7 in the ones place is the same as 7x1, the 9 in the tens place is...

An attempt at an optimal trial division primality test using the Sieve of Eratosthenes.

Why is factorization hard, yet generating primes easy? Where do we go from here?

How can we estimate the number of primes up to x?

Setting up the problem of a primality test.

Sieve of Eratosthenes allows us to generate a list of primes.

Try several practice two-step equation word problems. Answer correctly and move on; answer incorrectly and Khan Academy provides relevant tutorials.

Do you understand how two-way tables really work? Here's your chance to practice. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.

Practice interpreting two-way frequency tables. For example, what does the cell in the top left tell you? Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.