Most thermometers offer readings in both Celsius and Fahrenheit; however, some simple digital models may offer only Fahrenheit temperature information. Converting thermometer readings from Fahrenheit to Celsius requires use of a simple mathematical equation. This equation allows you to exactly calculate the Celsius temperature reading from the Fahrenheit reading without the use of charts or graphs. You may wish to use a calculator to work the equation to ensure you get the answer right or to double-check your work.

- Skill level:
- Easy

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## Instructions

- 1
Obtain the Fahrenheit temperature reading from the thermometer. This is the number you'll start with in the temperature conversion equation.

- 2
Subtract 32 from the Fahrenheit reading. For example, if the Fahrenheit reading is 37.8 degrees C, then you would subtract 32 from it to get 68.

- 3
Multiply that number by 5/9 to get the Celsius reading. If the number is 68, for instance, then multiplying it by 5/9 would yield a Celsius temperature reading of 37.8 degrees Celsius.

- 4
Check your work, if desired. Multiply the Celsius temperature by 9/5, then add 32 to the result. If you were checking the example problem, you would multiply 37.8 by 9/5 to get 68. Then, add 32 to 68 to get 100, which is the temperature you started with in Fahrenheit.