Celsius or Fahrenheit?

Celsius or Fahrenheit? lesson plan

Why do some thermometers show two different temperatures? Students create their own dual-scale thermometer.

  • 1.

    Thermometers are instruments that measure temperature using Fahrenheit (F) and/or Celsius (C) scales. The freezing point of water is 32 degrees F and 0 degrees C. Students compare thermometers with both scales then invent their own. Here are some ideas.

  • 2.

    Draw a thermometer. Use Crayola® Erasable Colored Pencils to draw a mercury-style thermometer on posterboard. Punch holes in the top and bottom. Mark F for the Fahrenheit side and a C for the Celsius side. Write in numerals and degree lines with a Crayola Fine Line Marker.

  • 3.

    Decorate it. On construction paper, draw and color items that represent hot and cold weather such as snowflakes, penguins, or sunglasses. Cut them out with Crayola Scissors. Attach them to the poster with a Crayola Glue Stick. Design a border.

  • 4.

    Add the "mercury." Measure and cut one red and one white ribbon that are each as long as the distance between the two holes. Tape one end of each color together. Thread through the holes and tape the other end.

  • 5.

    What’s the temperature? Find out the current indoor or outside temperature. Display it on your thermometer.


  • LA: Read with sufficient accuracy and fluency to support comprehension.
  • LA: Write informative/explanatory texts to examine a topic and convey ideas and information clearly.
  • LA: Report on a topic or text or present an opinion, sequencing ideas logically and using appropriate facts and relevant, descriptive details to support main ideas or themes; speak clearly at an understandable pace.
  • LA: Adapt speech to a variety of contexts and tasks, using formal English when appropriate to the situation.
  • SCI: Ask questions about the natural and human-built worlds.
  • VA: Intentionally take advantage of the qualities and characteristics of art media, techniques, and processes to enhance communication of experiences and ideas.
  • VA: Select and use the qualities of structures and functions of art to improve communication of ideas.


  • Students research a third system of measurement (Kelvin). Create a chart depicting the uses of each system.
  • In small groups, students take daily temperature readings using both the Celsius and Fahrenheit scales. Students plot a graph showing the results.