Fahrenheit to Celcius Conversions for the Adult ESL Learner

Learning Outcome

At the end of the lesson students will be able to calculate, with 80% accuracy, at least 4 temperature conversions

At the end of the lesson students will be able to share the local temperature with at least one family member in their country of origin, as they convert °F to °C


1. Pre-teach students the mathematical terms in English: 

-=Minus;                      +=Plus;             X=Times;         :=Divided by;               =Equals; °=Degree;                    .=Point in Math, Period in writing, Dot in internet lingo;

2. Tell students that 32° Fahrenheit = 0° Celsius.


The formula is:

Degrees Fahrenheit = (degrees Celsius X 2) + 30. 

Degrees Celsius = (degrees Fahrenheit – 30) : 2.

For example:

70°F-30=40      40:2=20°C                                            35°C X 2=70     70+30=100°F

56°F-30=26      26:2=13°C                                            10°C X 2=20     20+30=50°F

15°F-30= -15    -15:2= -7.5°C                                       5°C X 2=10       10+30=40°F


Have students use any number as temperature to practice the conversion.

Ask students to work in pairs, or alone to compute the conversion.

Then have students come to the board and write their calculations for all to see. Ask other students to support and encourage the student at the board. As a class, work out any corrections.


1.      You can give students a work sheet with some temperatures that need conversions.

2.      You may choose to start the next class by writing a few temperatures on the board, and ask students to come up to the board to convert them.

3.      You will need to review the formula for new students at the next class. You could ask the students who were present before to show newcomers how to do the calculations.

Additional information

·         http://www.livescience.com/39916-fahrenheit.html

The Fahrenheit and Celsius scales converge at minus 40 F, so that minus 40 F and minus 40 C represent the same temperature.

Today, the scale is primarily used in the United States, and is also used in the Cayman Islands, Palau, Bahamas and Belize. While other branches of science use the Celsius scale, U.S. meteorologists continue to use the Fahrenheit scale for weather forecasting and reporting. Canadian meteorologists sometimes use the Fahrenheit scale alongside the Celsius scale.

·         If you want to show your students how to convert temperatures accurately, you can visit: 


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