How to Convert Temperature From Fahrenheit to Celsius

Series Summary

Mathematics is used in virtually every aspect of everyday life. From the basic rules of counting, calculating and measuring, to complicated theorems and formulas, math forms the basis for what is absolutely known fact. Incorporating elements of logic and abstraction, mathematics is found in many career fields, such as the natural sciences, the medical field, engineering and even music. In this free video series, a math teacher demonstrates how to perform a number of math calculations and how to use math formulas, along with some tips on conversions, evaluating fractions and working with integers. Discover how to convert the temperatures from Fahrenheit to Celsius, how to change liters to milliliters and how to find the area of a rectangle. Measure square footage, graph, multiply exponents and reduce fractions. Improve basic math skills with these math lessons!

Video Transcript

"Hi, I'm Steve Jones. I want to tell you how to convert degrees Fahrenheit to Celsius. And be careful, sometimes people say degrees Celsius, but the old term is degrees Centigrade, but we say to Celsius without the word degrees. So initially, we've got the temperature 72 degrees Fahrenheit. And we know on the Fahrenheit scale, that 32 degrees Fahrenheit is the ice point -- that is, the freezing point -- of water. And 212 degrees Fahrenheit is the boiling point of water. And the equivalents in Celsius are zero Celsius, and 100 Celsius. It's these two facts that we're going to use to do our conversion. Now, the first thing to note is that 72 Fahrenheit, we have to reduce this by 32 because in that 72 degrees is 32 Fahrenheit degrees to get it to zero. So the first thing we do is subtract 32, which gives us 72 degrees Fahrenheit minus 32 gives us a number 40. Now, it's not a...it's not degrees, it's not anything. It's just a number 40. It's a pre...it's an intermediate stage. The second is we have to use the fraction because in this interval, there are 100 units, but in the Fahrenheit interval, there are 180 units, which means that these 40 Fahrenheit units represent less Centigrade units. The Centigrade unit is bigger. And therefore, what we have to do is multiply by a ratio of, well, 100 divided by 180. 100 over 180. This will scale down this to give us our Centigrade result. And this will give, using the 40 that we've got, having subtracted our 32 initially, 40 multiplied by 100 and divided by 180. Now, this is not a major mathematical problem. This is 4,000 divided by 180, and just simple canceling, and then this will come down to 9. It's 200 over 9. Now, everybody knows that something divided by 9 is going to give you a recurring number. So nines into 20 goes, two nines are 18, and you'll find it's 22.2 recurring...22 degrees. So this would be 22 Celsius. So 72 Fahrenheit...72 degrees Fahrenheit converts, through this process, into a temperature of 22 Celsius."