Math Operators

Quick reference

• 00:04 In the next video, I want to talk about number data types.
• 00:08 But before that, in this video, I want to just talk about basic math and
• 00:11 the math operators.
• 00:13 So to do math in Python, it is super, super easy.
• 00:16 We just use the same math symbols that you learned in grade school math for
• 00:21 basic math operations, addition, subtraction,
• 00:24 multiplication, division, exponents, and modulus.
• 00:27 And you're probably familiar with exponents we'll talk about it in a second,
• 00:30 but the modulus here may be something you haven't seen before,
• 00:33 we'll get into that in just a minute as well.
• 00:35 So to do math in Python super, super easy, could not be easier.
• 00:40 You just go print, just like whenever we want to print something to the screen.
• 00:43 Now you don't have to use print to use math, but if you want to print the outcome
• 00:46 of your math onto the screen, obviously you need to use print.
• 00:49 So we can just go 2 + 3, if we save this and run it,
• 00:53 it's going to be five obviously.
• 00:56 So math is really just this easy in Python.
• 01:01 So 10- 3, obviously is going to be 7.
• 01:03 To multiply you just use this star.
• 01:06 Save that, 30, and to divide, let's make this a nice and round number.
• 01:12 We just use the forward slash.
• 01:14 Remember we did the backslash to escape something out.
• 01:18 This is the forward slash, that means divide.
• 01:20 So if we save this it's going to be 5.
• 01:22 Super easy.
• 01:23 So exponents, you're taking something to the power of something.
• 01:27 So if we took, for instance, 2 to the power of 3,
• 01:31 we would use this double multiplication sign, which means exponents.
• 01:36 So 2 to the 3rd power would be basically the same as 2 * 2 * 2.
• 01:42 Now if it was 2 to the 4th power, it would be * 2, 4 times, 1, 2, 3, 4.
• 01:49 Here we have 3 *, so it's 1, 2, 3 quick exponent primer.
• 01:54 If we save this 2 * 2 * 2, 2, 4, so it's going to be 8, right, yep, 8.
• 01:59 So that just leaves the modulus.
• 02:01 And the modulus kind of can confuse people sometimes.
• 02:04 And it's actually very useful for a lot of different things and
• 02:07 we'll see you later on in the course.
• 02:09 But if we were to take 10 divided by 3, well, 3 goes into 10 three times.
• 02:15 So 3 times 3 is 9, right?
• 02:16 Well, 10 minus 9 is 1.
• 02:19 So 3 with 1 remainder with 1 leftover.
• 02:23 Well, the modulus returns that remainder, that leftover thing.
• 02:26 So if we save this and run it, we'll get one because that's the remainder.
• 02:31 The modulus just returns the remainder.
• 02:33 So super useful if we had 2, 10 divided by 2 is 5 with no remainder,
• 02:38 there's no leftover because 5 times 2 is 10.
• 02:41 So if we run this, we're going to get 0.
• 02:44 So that's the modulus, super easy.
• 02:46 The only kind of weird thing about math is something called order of operations.
• 02:49 And you probably remember this from grade school math.
• 02:51 But if we have 2 + 3 * 2, what is the answer going to be here?
• 02:57 Is it going to be 2 + 3 equals 5 times 2 equals 10?
• 03:03 Or is it going to be 3 times 2 is 6 plus 2 equals 8.
• 03:09 Care to make a guess?
• 03:10 Well, the answer is going to be eight and that's because of the order of operations.
• 03:14 In math, in math world there's a hierarchy of which things get done first and
• 03:20 multiplication and division are more important than addition and subtraction.
• 03:24 So they get one first and then the addition or
• 03:26 subtraction gets done afterward.
• 03:28 So in this case we're taking 3 * 2, which is 6, and then adding 2 and we get 8.
• 03:33 You can override this, and you do that with more parentheses.
• 03:38 So, for instance, we could go wrap these guys in parentheses.
• 03:42 And in the world of order of operations parentheses are more important than
• 03:46 multiplication and division.
• 03:48 And therefore also more important than addition and subtraction.
• 03:52 Basically what it means is anything inside of these parentheses
• 03:54 is going to be done first and then outside your normal order of operations,
• 03:58 your normal precedence takes over.
• 04:01 So we have 2 + 3 equals 5, times 2 equals 10.
• 04:04 If we run this, boom, we get 10.
• 04:06 So that's math.
• 04:07 That's order of operations, which is very, very basic.
• 04:10 And in this video, we took these and we just wrote the numbers right in here.
• 04:15 You could also put num 1 = 1, num 2 = 2.
• 04:23 And then with variables you go num 1 + num 2,
• 04:27 save this we should get 3, and we have 3.
• 04:31 So we can use the numbers themselves.
• 04:33 You can use variables.
• 04:34 You can use all these different operators and these signs +,
• 04:38 -, *, /, these are called operators.
• 04:41 They're the math operators.
• 04:42 So if you hear the word math operators, it just means math sign.
• 04:45 So that's all for this video.
• 04:46 In the next video we're going to look at the numbers data
• 04:51 types specifically floats and integers.

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