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These are the user uploaded subtitles that are being translated: 1 00:00:00,990 --> 00:00:04,510 Hello everyone and welcome to the Arithmetike with our lecturer. 2 00:00:04,630 --> 00:00:10,050 It's going to be a relatively short lecture just showing how to do basic mathematics with our let's 3 00:00:10,050 --> 00:00:13,190 go ahead and jump to our studio. 4 00:00:13,200 --> 00:00:18,200 All right so here we are our studio and we're going to be just doing really basic math. 5 00:00:18,240 --> 00:00:22,380 We're just going to be using the console so don't worry about writing in our script for this unless 6 00:00:22,410 --> 00:00:24,830 you want to keep a history of what we've done. 7 00:00:24,910 --> 00:00:28,090 So go ahead and push the con. ups we can see it. 8 00:00:28,320 --> 00:00:33,800 And let me go ahead and just show you how to do some basic arithmetic with our first off just edition 9 00:00:34,220 --> 00:00:36,900 addition can be done with just a plus sign. 10 00:00:37,290 --> 00:00:41,400 And then you can almost These are just as a simple calculator which is basically going to be doing for 11 00:00:41,400 --> 00:00:42,300 this lesson. 12 00:00:42,460 --> 00:00:46,190 Go ahead and click enter to run that and you have one plus two is three. 13 00:00:46,380 --> 00:00:50,490 Again just the number and another number. 14 00:00:50,490 --> 00:00:51,470 Cetera. 15 00:00:51,750 --> 00:00:55,000 And you can do this with floating point numbers as well. 16 00:00:55,020 --> 00:00:57,950 So that's numbers of a decimal in them. 17 00:00:58,400 --> 00:01:02,980 You can see that the decimals are added up just as you would expect subtraction. 18 00:01:03,150 --> 00:01:05,990 As you might have guessed it's just going to be a minus sign. 19 00:01:05,990 --> 00:01:12,780 So do five minus three to notice that you're probably going to want to try your best to use spacing 20 00:01:12,780 --> 00:01:14,730 for readability. 21 00:01:14,730 --> 00:01:20,370 So here I would say five minus three is more readable in the second iteration than the first one. 22 00:01:20,490 --> 00:01:22,500 First one kind of looks like just five space. 23 00:01:22,500 --> 00:01:24,970 Negative three which is technically the same thing. 24 00:01:25,110 --> 00:01:30,080 The way are is going to read it but you always want to make your code as readable as possible for division 25 00:01:30,120 --> 00:01:30,400 . 26 00:01:30,520 --> 00:01:32,500 Just going to be a slash. 27 00:01:32,580 --> 00:01:38,160 So that's one divided by two 0.5 and the vision is going to perform what's known as true division. 28 00:01:38,160 --> 00:01:40,250 So Ill perform division. 29 00:01:40,320 --> 00:01:42,740 And keep in mind the decimals. 30 00:01:42,780 --> 00:01:50,460 So the remainders etc. all right for exponents or to the power of you can use a little carrot symbol 31 00:01:50,460 --> 00:01:50,480 . 32 00:01:50,490 --> 00:01:53,050 So that's above the 6 on a keyboard. 33 00:01:53,070 --> 00:01:56,250 So two to the power of three is eight. 34 00:01:56,610 --> 00:02:02,790 And do say four it's the power for 256 etc.. 35 00:02:02,880 --> 00:02:09,480 All right well one other note is that order of operations is followed in are as you would just expect 36 00:02:09,540 --> 00:02:10,600 to be. 37 00:02:10,800 --> 00:02:25,180 So for example if I said a hundred times two plus 50 divided by two and put those together I get 225 38 00:02:25,200 --> 00:02:25,490 . 39 00:02:25,590 --> 00:02:27,390 So order of operations is followed. 40 00:02:27,390 --> 00:02:33,120 Meaning I'm going to do 100 times to first to get 200 than 50 divided by two. 41 00:02:33,120 --> 00:02:41,520 Since division is the next one up which is 25 and then 200 plus 25 is 225 if I want to actually specify 42 00:02:41,550 --> 00:02:44,780 particular orders of operations I can use parentheses. 43 00:02:44,970 --> 00:02:50,610 So for example I could say something like 100 times and with parentheses designate that I wanted to 44 00:02:50,610 --> 00:02:58,210 actually add 2 plus 50 first and then divide right to accepter. 45 00:02:58,470 --> 00:03:01,610 OK so everything's working probably as you would expect it to. 46 00:03:01,620 --> 00:03:03,840 Just basic arithmetic. 47 00:03:04,110 --> 00:03:11,040 The last operation I want to show is the motter modular operation which basically just returns the remainder 48 00:03:11,040 --> 00:03:12,470 of a division. 49 00:03:12,480 --> 00:03:18,720 So for example if I say five divided by two I want to get two point five. 50 00:03:18,840 --> 00:03:24,570 So that means that two times two is four and I have a remainder of 1 right. 51 00:03:24,570 --> 00:03:29,040 So by about about 2 is 2.5 if I actually want to get the remainder. 52 00:03:29,040 --> 00:03:35,680 I can use the modulo operation which in R is two sets of percentage signs. 53 00:03:36,270 --> 00:03:39,890 So that can be read as 5 2 and the remainder is 1. 54 00:03:39,900 --> 00:03:43,370 And all this is doing is just returning in the remainder of a division. 55 00:03:43,740 --> 00:03:56,250 So for example if I say 10 maade something like 8 I'll get two since a can only go into 10 once with 56 00:03:56,250 --> 00:03:57,710 a remainder of two. 57 00:03:57,960 --> 00:04:00,080 Since eight plus two is equal to 10. 58 00:04:00,120 --> 00:04:04,230 So that's just going to give you the remainder in a division. 59 00:04:04,230 --> 00:04:09,630 This is really useful later on for checking if numbers are even or odd or third divisible by a certain 60 00:04:09,630 --> 00:04:10,300 number. 61 00:04:10,300 --> 00:04:11,160 Cetera. 62 00:04:11,280 --> 00:04:11,860 OK. 63 00:04:12,060 --> 00:04:14,130 Hopefully those are all pretty straightforward. 64 00:04:14,130 --> 00:04:18,390 You can just review this lecture or the notes for this lecture in case you ever want to reference what 65 00:04:18,390 --> 00:04:21,190 the actual symbols or operations are for arithmetic. 66 00:04:21,500 --> 00:04:27,740 OK that's it in the next lecture We'll talk about some basic data types in here. 67 00:04:27,750 --> 00:04:29,410 Thanks everyone and I'll see you at the next lecture 6693