WEBVTT 00:00.590 --> 00:08.930 Numbers are used quite often in programming to keep scoring games, represent data visualization, stored 00:08.930 --> 00:11.240 information in web applications and so on. 00:11.270 --> 00:18.020 So Python threads numbers in several different ways depending on how they are being used. 00:18.200 --> 00:24.620 Let's first look at how Python manages integers because they are the simplest to work with. 00:25.360 --> 00:25.630 Here. 00:25.630 --> 00:26.580 We will do it. 00:26.610 --> 00:28.590 This run again. 00:28.600 --> 00:30.130 Here now. 00:32.330 --> 00:35.570 Firstly, we will start with integers. 00:35.720 --> 00:37.760 Now let's change the color. 00:43.190 --> 00:44.330 Integers. 00:47.010 --> 00:49.620 So you can do math with integers, of course. 00:49.620 --> 00:51.060 Here now. 00:53.640 --> 01:03.750 For example, my integer or my value here, two plus three and print my value. 01:04.580 --> 01:05.140 I see here. 01:05.140 --> 01:06.430 Five two plus nine. 01:06.480 --> 01:07.330 Nine nine. 01:10.770 --> 01:11.580 Doesn't one. 01:12.480 --> 01:14.400 You can do subtraction. 01:16.710 --> 01:19.370 And it's 9.97 multiplication. 01:21.160 --> 01:22.120 And division. 01:24.620 --> 01:26.360 In terminal session. 01:26.360 --> 01:33.500 Python simply returns the results of the operation, and Python uses two multiple action symbols to 01:33.500 --> 01:35.600 represent exponents. 01:35.810 --> 01:39.050 So here this is exponent exponential here. 01:39.050 --> 01:41.630 As you can see here, there's a lot of numbers here. 01:42.630 --> 01:42.930 Go. 01:44.650 --> 01:48.160 You can see here, we can do this. 01:52.440 --> 01:54.140 The second one I show here. 01:54.140 --> 02:01.400 So Python supports the order of operations too, so you can use multiple operations in one expression. 02:01.400 --> 02:08.270 So you can also use parentheses to modify the order of operations so Python can evaluate your expression 02:08.270 --> 02:12.650 in the order you specify, for example, like this. 02:13.190 --> 02:19.790 Uh, two plus two plus nine, multiply by four. 02:21.040 --> 02:22.900 Here it's 44. 02:22.900 --> 02:29.740 And the spacing in these examples has no effect on how Python evaluates the expressions here. 02:34.230 --> 02:35.040 Like this. 02:35.550 --> 02:36.000 This will. 02:36.330 --> 02:39.240 But this has no effect on Python. 02:39.390 --> 02:47.040 But it simply helps you more more quickly spot operations that have priority in your reading throughout 02:47.070 --> 02:48.750 your code. 02:49.710 --> 02:53.310 And we also have lots. 03:06.140 --> 03:13.370 So Python calls any number with a decimal point a float. 03:13.730 --> 03:20.060 This term is used in most programming languages, and it refers to the fact that a decimal point can 03:20.060 --> 03:23.300 appear at any position in a number. 03:23.330 --> 03:28.430 Every programming language must be carefully designed to appropriately manage decimal numbers so numbers 03:28.430 --> 03:31.940 behave appropriately no matter where the decimal point appears. 03:31.970 --> 03:37.210 So for the most part, you can use floats without worrying about how they behave. 03:37.220 --> 03:44.450 Simply enter the number numbers you want to use and the python will most likely do what you expect. 03:44.720 --> 03:46.490 Like this here for example. 03:46.490 --> 03:49.700 0.1 multiply by or. 03:53.020 --> 03:57.800 0.9 here it's 1.0999. 03:58.060 --> 04:01.100 1.099. 04:01.180 --> 04:05.440 And we also have here sample. 04:06.540 --> 04:06.990 Do. 04:07.900 --> 04:12.340 1999 multiply by 0.1. 04:13.330 --> 04:15.810 And 9.9. 04:15.960 --> 04:22.200 However, be aware that you can sometimes get an arbitrary number of decimal places in your answer. 04:22.530 --> 04:30.540 For example, this 0.90.2 here plus 3.1. 04:31.020 --> 04:33.330 And as you can see here, we get this. 04:33.540 --> 04:38.910 So this happens in all languages and this is of little concern. 04:38.910 --> 04:46.560 So Python tries to find a way to represent the results as precisely as possible, which is sometimes 04:46.560 --> 04:51.120 difficult, even how computers have to represent numbers internally. 04:51.120 --> 04:56.880 So just ignore the extra decimal places for now so you will learn ways to deal with the extra places 04:56.880 --> 05:01.530 when you need to in the projects of Part two. 05:01.890 --> 05:09.240 And we also said so when you divide in two numbers, even if they are integers that result in a whole 05:09.240 --> 05:10.020 number. 05:10.020 --> 05:18.700 So you will always get the float here, for example, divide four by two and the 2.0. 05:18.700 --> 05:26.070 So if you mix an integer and a float in any other operation, you will get a float as well. 05:26.080 --> 05:33.670 Look, this oops here, one one plus 5.0. 05:33.670 --> 05:36.190 And as you can see, it's 6.0. 05:36.400 --> 05:41.740 So Python defaults to a float in any operation that use the flow. 05:41.740 --> 05:44.410 So even if the output is a whole number. 05:45.550 --> 05:52.210 We also have underscores in numbers, which you will learn in next lecture.