### Video Transcript

What is 90 degrees Fahrenheit in degrees Celsius? Give your answer to one decimal place.

In this question, we’re asked to take a temperature that’s being measured in degrees Fahrenheit and express it in degrees Celsius. To do this, we need a conversion formula, which looks like this. The temperature in Celsius is equal to five over nine times the temperature in Fahrenheit minus 32. So we need to substitute in our temperature in Fahrenheit, represented by 𝑇 sub 𝐹 in the formula, to convert that temperature into degrees Celsius, which is given by 𝑇 sub 𝐶 in the formula. In other words, we just replace 𝑇 sub 𝐹 with 90.

To work out the answer, we can start by simplifying the part of the expression inside the parentheses. 90 minus 32 is 58. And then, we can take the whole thing into our calculator, which gives us an answer of 32.2 recurring. And now, we have units of degrees Celsius. This question asks us to give our answer to one decimal place. So we find our first decimal place, which is here. And we look at the decimal place immediately after it, to tell us whether the first decimal place should be rounded up or whether it should stay the same. Because the second decimal place is less than five, that means the first decimal place should stay the same. We don’t round up, which gives us our final answer.

90 degrees Fahrenheit is equal to 32.2 degrees Celsius to one decimal place.