# Conversion Chart

*Material Required**: Graph sheet and pen.*

Students in the high school often need to convert temperature measurements from the Celsius scale to the Fahrenheit scale and vice versa. This activity aims at making a chart for converting from one scale to another.

Ask the students to plot the different scales on the X and Y axis on a graph paper. Let them obtain the conversion for three different values of temperature using the formula . Ask them whether the three points lie on a straight line. Let them draw a straight line through these points. Are the temperatures of the ice point and steam point shown correctly in both degree Celsius and degree Fahrenheit by the straight line? Ask the students to verify whether the line can be used as a chart to convert any measure of temperature from Celsius to Fahrenheit. Why is this possible?

The chart provides an occasion to discuss the property of linear functions. Let the students explore making charts of other linear functions such as converting inches to centimetre, or a chart for finding the father’s age from the son’s age and so on.