General Science

Explore & Learn

AMNH Ology

Discovery Kids

National Geographic

NOVA

CA Academy

How Stuff Works

UEN Science Interactives

NASA Kids Club

Science Bob

Understanding Science

DK Find Out

PHET Interactive

Physics Classroom

Science For Kids
Science Buddies 

Science Videos
SciShow
SciShow Kids
Crash Course
Mystery Doug
Science Max

Sick Science
Minute Physics

Minute Earth
ASAP Science

JLab Videos

The Kid Should See This

Science Fair Sites
Science Fair Central
Dragonfly TV Science Fair
Super Science Fair Projects
Battery Kids 

Science News
DOGO News
Sci News for Students
Science Alert
Newsela Science
DoSomething.org
CNN10 Students

Inventions
Inventions A to Z
Technology Timeline
At A Glance
Thought Co Inventors
On This Day Inventors
Time for Kids - Inventors

Math & Science Careers
Cool Science Careers
Environmental Science Careers

Measurement Resources

VL: The Metric System

AAAMath - Measurements

How Do You Measure Up

Cyberchase - Measurement

NIST Measurement League
Candy Shop - Mass/Volume 

Conversion Tools

AskNumbers.com

WorldWide Metric

ConvertUnit.com

Science Made Simple

GoodCalculators.com 

Online Activities
Making Measurements
QUIA: Metric Mania
QUIA: Metric Measurement
Taking America's Measure