Basic Math

Quick reference

• 00:04 One of Excel's main purposes is to be an analytics tool to take numbers and reformat them and run them through different scenarios to
• 00:11 try and come up with what an output scenario might look like. We can use all kinds of incredibly
• 00:17 complex math and look-up formulas and all kinds of different things to make that happen but
• 00:21 in order to actually unlock those we have to understand the true
• 00:25 basics of formulas. So that's what we're going to look at right now.
• 00:29 Assume right now that we're looking at this particular inventory of our sport store
• 00:33 and we want to try and figure out, we've got a quantity, we've got a
• 00:36 cost per unit, we would like to figure out what the total value of our inventory is.
• 00:42 So in order to do that we're going to go and we're going to say add a column called say, worth and
• 00:48 what I need to do is I need to figure out how do I calculate 56 times 8.99.
• 00:54 We don't want to reach for a calculator because quite frankly Excel is the world's best calculator. And the way that we
• 00:59 actually start this is we start with equals and the reason we're doing this is we say I want to know
• 01:03 that cell D5 equals what? I want it to equal 56 times and for the times we use the asterisk key
• 01:13 8.99. So this is the mathematical equation 56 multiplied by 8.99. When we hit Enter, Excel will calculate it for us as 503.44.
• 01:25 Now this is great but
• 01:26 the challenge is I can't copy this formula down and paste it in my next row because
• 01:31 it's still going to multiply 56 times 8.99. Wouldn't it be cool
• 01:36 if I could actually say you know what, the value that's in this cell really should be what's
• 01:41 in this cell times what's in this cell. Well we can do that as well.
• 01:45 So what I'm going to do is type in equals, I'm going to say give me equals B5 times
• 01:52 C5.
• 01:54 When I hit Enter you'll see that it still comes to 503.44.
• 01:58 But if I copy this formula down,
• 02:01 let's go copy and paste it into all this area here. We'll go right click and we'll paste it.
• 02:06 You'll see that now the 669.48
• 02:10 well that just happens to be 84 times 7.97.
• 02:14 And we can actually prove that by saying equals 84
• 02:18 times 7.97
• 02:21 Enter. And you'll see that the number comes back as the same. The reason being is
• 02:25 when I copy this down you can see that the formula that's here is
• 02:29 multiplying these two cells. Now we'll talk about absolute versus
• 02:33 relative cell referencing and why these formulas carry down and change in another video.
• 02:39 But the secret that we want to look at here is we can multiply individual cells by other cells.
• 02:45 We could also go and say you know what I want the total quantity of
• 02:49 all of these things here. So how am I going to get that? Well I can say equals
• 02:54 because we always start off with equals, it's kind of like an adding machine in a way. B10 equals what?
• 03:00 Well it equals 56 plus
• 03:03 84 plus 21
• 03:06 plus 65
• 03:09 plus 52. When I hit
• 03:12 Enter it'll come back with 278.
• 03:14 I can verify this by saying lets select all these cells and look down at the
• 03:21 quick info area here and the sum is 278. So my formula looks like it's correct which is great.
• 03:28 The mathematical operators that we look at when we're working in Excel are: for multiplication we use the asterisk key,
• 03:37 for division we'll use the slash key,
• 03:41 for addition plus, for subtraction minus and for exponents we use the
• 03:48 little hat that is shift 6 on the North American keyboard. I believe it's similar in other countries.
• 03:54 So those are the five mathematical symbols that we'll end up using
• 03:59 and we'll look at more mathematics later on in these video courses but those are the keys you want to work with.
• 04:06 There is also something else that we can do as well. I am going to get rid of this
• 04:10 278 because Excel's got this cool little feature that we can use which is called the
• 04:14 auto sum. So if I'm sitting in an area below my column of data, up here on the Home tab I've got this AutoSum button
• 04:22 and if I click down here I got a few different options that it'll let me do.
• 04:27 When I click Sum
• 04:29 it'll actually go in and say I'm going to give you a formula equals sum and it's giving me my range
• 04:34 B5 through B9 and we'll look at understanding all these a little bit later,
• 04:39 I hit Enter it'll give me the same sum. So if we ever want to to look at that, we go here click the AutoSum button
• 04:47 it'll actually give us the sum of all of our worth column as well. So
• 04:51 you don't even have to know how to write these formulas
• 04:54 as long as you can click in the right place and click the AutoSum button it will sum
• 04:57 everything above it and again we can verify that by selecting this
• 05:02 looking down at the bottom corner here this is
• 05:04 1924.08. So this is a
• 05:07 nice way to actually go through and save
• 05:09 yourself having to say
• 05:10 equals this, plus this, plus this, plus this all the way through the entire scenario.

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