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Becoming Familiar with SI

The SI (metric system) is easy to use! Learn everyday SI reference points

Learning the SI (International System of Units, commonly known as the metric system) requires developing just a few reference points - a general indicator you can use to orient yourself. Reference points help build that innate understanding of "how much." The metric system is a complete measurement system made up of 7 base units. Once you are familiar the SI basics you are ready to go! HINT: Learning the SI is not about making unit conversions in your head (this will only slow you down). Check out these resources to learn to "think metric"...

View the Universe! Then move through space towards the Earth in successive orders of magnitude until you reach the subatomic universe of electrons and protons.

Nanotechnology - learn about the very small. Discover the scale of things - check out super small natural and man made items from the nano world!

  • Scale of Things - Nanometers (chart) - PDF
  • The Size of Nanoscale. These examples can help you understand just how small a nanometer is (one-billionth of a meter).
  • What is Nanoscale? Try out this activity to see how everyday objects compare to the nanoscale.
  • How the Nanoscale Measures Up (National Geographic Society) Hands-on activities help students explore the nanoscale and how it compares to the macro and micro scales.  Incorporate mathematics and visual media.
  • How Small is Nano? (Video – NISE) What is a nanometer? What things are measured in nanometers? This video explores the macro, micro, and nano scale. (available in Spanish)
  • How Small is Nanotechnology? Explore these activities to learn how scientists measure at the nanoscale.
  • How Small is Small (Lesson Plan) – What is a Microorganism? (NPS – Zion NP) – Students conceptualize the size of microorganisms by using a large scale model of specific organisms.
  • The Micro and Macro Worlds (NNIN) This activity focuses on scale and the importance of using scale bars when presenting nanoscale structures.
  • How Big Is It? is an activity that introduces the nanoscale using the metric system (Stanford University).
  • How Big is a ...? This animation compares the relative sizes of cells and organisms.
  • Relative Sizes and Detection Devices (Florida State University)
  • How Small is Small? Play a game! Can you arrange these objects from smallest to biggest? Sure, it's fun!


Created April 13, 2010, Updated October 27, 2020