PBS
Pbs: Word Problems Using Addition and Subtraction of Fractions: Harry Gets Locked Up
This video features Harry and his cousin Harley. Harley is desperate to use Harry's bike, but first he must decipher the combination to the bike lock by solving a word problem. In the accompanying classroom activity, students complete a...
University of Illinois
University of Illinois: Mste: The Binary Calculator Applet
The binary number system is used to represent data in digital form. This site provides a binary calculator that will convert between binary, octal, decimal and hexadecimal, perform simple addition and subtraction, and do compliment and...
Scholastic
Scholastic: Math Facts
This one page website from Scholastic offers two math facts games and a secret code idea all to help you remember your math facts.
PBS
Pbs Learning Media: Pattern Recognition: Cyberchase Games
Identify the patterns using addition, subtraction, and geometry to solve the puzzle and crack Hacker's code.