Data and Storage
Today, we'll learn how computers store information ("data"). We'll also learn how we can manipulate data in code.
Decimal  0 
Binary  0 
0101 (5) + 0111 (7)
0101 (5) + 1011 (11)
0111 (7) + 0011 (3)
1.875*2^2
Word Problems  Solution 

Alice has 600 MB of data. Bob has 700 MB of data. Will it all fit on Alice's 2 GB thumb drive? 
Yes it fits: 600 MB + 700 MB is 1300 MB. 1300 MB is 1.3 GB, so it will fit on the 2 GB drive no problem. Equivalently we could say that the 2 GB drive has space for 2000 MB, so the 1300 MB fits.

Alice has 100 small images, each of which is 500 KB. How much space do they take up overall in MB? 
100 times 500 KB is 50000 KB, which is 50 MB.

Your ghost hunting group is recording the sound inside a haunted Stanford classroom for 20 hours as MP3 audio files. About how much data will that be, expressed in GB? 
MP3 audio takes up about 1 MB per minute. 20 hours, 60 minutes/hour, 20 * 60 yields 1200 minutes. So that's about 1200 MB, which is 1.2 GB.

Character  ASCII value  ASCII (binary)  Huffman (binary) 

' ' 
32 
00100000 
10 
'a' 
97 
01100001 
0001 
'b' 
98 
01100010 
0111010 
'c' 
99 
01100011 
001100 
'e' 
101 
01100101 
1100 
'z' 
122 
01111010 
00100011010 
Source: Marty Stepp
Scheme  Lossless vs. Lossy?  Medium  Notes 

MP3  Lossy  Audio  10x less space, but still sounds good 
JPEG  Lossy  Images  Free and open source; very widely used and supported 
GIF and PNG  Lossless  Images  PNG is a little bit better; mostly used for nonphotographs 
The image on the right has been extremely compressed, taking up about 29% of the space as the image on the left.
myName
) without spaces and value ("Ashley Taylor"
)
=
) sign
prompt
+  * /
=
to store the result
parseInt("4")
gives you the number 4