CS 100 (Learn) — CS 100 (Web) — Module 04
NOTE: If your internet access is restricted and you do not have access to YouTube, we have provided alternate video links.
Note: This video transcript has been slightly modified. Corrections are marked with strikethrough, and alternative wording has been placed in [square brackets] to correct some of the awkward or confusing phrasing in the videos.
In this video we are going to review a very basic formula and then talk about what it means for something to be a formula.
I am going [revisit] cell D2 and I am going to enter into the contents of that cell equals (all formulas in Excel begin with the equal sign).
Whenever you want to do a formula you are always going to start it off with an equal sign. I am going to type 1 + 1 and hit enter.
Now the value what is displayed in the cell is the result of the calculated value 1+1 but the contents of the cell is a formula (=1+1).
I am going to rant because this course is being offered by the Faculty of Mathematics at the University of Waterloo and [we have high standards. The rant will be] about why that is not a very good term: "formula".
Let's talk a little bit about the terminology we use in mathematics. First, the number 1 is a value. We have already talked about values... it is a numeric value.
If I say "1+1" that in mathematics is what we know it is an expression... it has an operator and we will talk about operators in a [moment]. What you enter [in] Excel is "=1+1", which isn't a valid expression in mathematics.
What you are [entering] is half of an equation. What you are really saying (technically) in Excel is that cell D2 is equal to one plus one. [Now,] is that a formula? Well, not really. A formula is something from [an area of study] like physics, where you might have "force equals mass times acceleration".
[Traditionally,] that is usually what [mathematics] mean by a formula: you are showing a relationship between variables of a physical system (or something like that).
That is not what we are entering in Excel... we are actually entering just an expression, but then they throw an equal sign in front of it.
It does not make any sense at all. Calling it a formula is not cool because it is not really a formula. If anything, it is an expression... but that is what we enter in Excel.
[It] is not a formula, but for consistency sakes we are going to [call it] is a formula, and then every time I say formula just remember that the mathematician inside me is dying a little bit every time I call [it] a formula.
I want to make sure you know that is not a valid formula, but unfortunately [it] is the terminology [used with] Excel.
If I [enter] "=1+1", that is now a formula.