Use Base-Ten diagrams and standard, expanded, and word forms to represent numbers. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. Find Which One ...

Quick confession: This is my favorite time of year. I love all of it. In Pennsylvania, the leaves are just starting to turn colors. It’s turning cooler which means that I can open the windows and dig ...

Despite stark warnings that using Social Security numbers on many mailings is putting Californians’ identities at risk, the Employment Development Department has told the state auditor that it will ...

The Markov numbers reveal the secrets of irrational numbers and the patterns of the Fibonacci sequence. But there’s one question about them that has resisted proof for over a century. Most people are ...

SACRAMENTO, Calif. - The state auditor issued a scathing report on Thursday, saying that the Employment Development Department has sent out at least 38 million pieces of mail with people's Social ...

A shard of smooth bone etched with irregular marks dating back 20,000 years puzzled archaeologists until they noticed something unique – the etchings, lines like tally marks, may have represented ...