# Math resources

 2 1 A little embarrassed to say this but during unit 1 with the simple conversions of converting the speed of light into nanosticks or whatever I was a bit confused by the simple algebra..Does anyone know any excellent preferably free math resources concerning math you'd find in computer science such as algebra,calculus,trig etc? asked 28 Feb '12, 18:52 e0s-2 705●1●4●22 accept rate: 71%

 6 The Khan Academy - awesome resource for free videos and brushing up on math, all the way from 1+1 up to Calculus, Linear Algrebra, etc However, everything that's been needed in this course so far, they didn't expect us to have any math skills. They've given numbers and said "just multiply these" or whatever, but there hasn't been any complicated math anywhere along the way. answered 28 Feb '12, 18:55 Rob Barnes-3 ♦ 19.1k●10●68●205 This is a great resource. If you start with the arithmetic exercises and do the work in your head, you'll be amazed at the calculations you can learn to do. (17 Mar '12, 10:44) Graeme Here is the video for the Converting within the metric system from the khanacademy (17 Mar '12, 11:16) Emilio Garcia-1
 4 For conversion problems I always put the units in square brackets, and make sure that I end up with the right units in the end. I think that it's known as dimensional analysis? For example lets say that I'm trying to find how far light travels in a picosecond in terms of millimeters: x [mm/ps] = 299,792,458 [m/s] * 1000 [mm/m] * 1 [s] / 1,000,000,000,000 [ps] x [mm/ps] = 0.299 [mm/ps] (helps to explain the packet of pepper in the Grace Hopper video) If you're doing it on paper then you can cross out any units that appear in both a numerator and demoninator, and check that you wound up with the right units. If not then play around until you do. Does this help? answered 28 Feb '12, 19:40 Keith Evans 2.0k●10●21●42 I think it¡s more easier like this, I'll round the speed of light: v[km/s]=300 000 km/s= 300 000 000 m/1000000000000 ps= 300 000 000 000 mm / 100000000000 ps= 0.3 mm/ps If you can understand scientific notation: v[km/s]=3x10^5 km/s= 3x10^8 m/1x10^12 ps= 3x10^11mm / 1x10^12 ps= 0.3 mm/ps Of course I had to look up that 1ps=10^-12s or 1s=10^12 ps (17 Mar '12, 10:32) Emilio Garcia-1
 2 You could also check out PurpleMath - They tend to provide a lot of good (and unique) explanations that use easier to grasp concepts. One of my favorites is the magic cubes they use to explain adding and subtracting negative numbers. I often recommend this site to teachers and students I work with (though Khan Academy is my favorite!). There are others, but let me know if this one works for you. answered 04 Mar '12, 14:32 Pamela Campb... 1.5k●4●18●39 I also had very good experiences with PurpleMath. (17 Mar '12, 10:45) ydnayabe-1
 0 Great, that did help KeithE, and thanks for the Khan Academy resource Velak. answered 28 Feb '12, 22:06 e0s-2 705●1●4●22 As I was driving home I thought of something that might be confusing to you, and it's related to the Grace Hopper material too. When people quote CPU speeds they typically say something like my Intel Core i5 core runs at 2.7 [GHz]. If you wanted to compute how far light travels in one clock cycle of this CPU, then it might be helpful to restate the [GHz] units as 2,700,000,000 [clocks/s] or [cycles/s]. Then you might want to solve: x [inches/clock cycle] = (1 [s] / 2,700,000,000 [clock cycles]) *( 299,792,458 [m] / 1 [s]) * (100 [cm] / 1 [m]) * (1 [inch] / 2.54 [cm]) = 4.37 [inches/clock cycle] I sure hope that I worked it out correctly, and that it saves you some confusion in the future. The wikipedia page "International_System_of_Units" might come in handy as well. (28 Feb '12, 23:24) Keith Evans
 0 Khan Academy also has some great vids on Python. EX: Introduction to Programs Data Types and Variables answered 28 Feb '12, 22:29 jwetzel 74●1●5
 0 I can't recommend Khan Academy enough. I was able to review probability and statistics as well as linear algebra over there enough for the CS373 class. You can pretty much learn everything through Vector Calculus over there! answered 17 Mar '12, 10:34 Joe Balsamo 5.3k●10●32●75
Question text:

Markdown Basics

• *italic* or _italic_
• **bold** or __bold__
• image?![alt text](/path/img.jpg "Title")
• numbered list: 1. Foo 2. Bar
• to add a line break simply add two spaces to where you would like the new line to be.
• basic HTML tags are also supported

×15,238
×101
×53
×42
×40