How much memory does your phone have? How big is your USB drive? How much RAM is in your laptop? For most devices, that number is a power of two. The computing world revolves around powers of 2. The earliest video game systems boasted 8-bit graphics. That’s 2^{3}. You can by a 16-, 32-, or 64-gigabyte flash drive. Why are powers of 2 so important?

#### Binary Logic

The circuit boards of every computer, smart phone, or gaming system is comprised of tiny switches. Each switch can either be on or off. Programmers use a number system called **binary** to describe these switches. When a switch is off, it is represented by a 0. When the switch is on, it is represented by a 1. The binary system is built around powers of 2. The number 1 in binary denotes 2^{0}, which is equal to 1. 10 in binary means 2^{1}, or 2. 100 in binary signifies 2^{2}, or 4.

When we talk about how much memory something has, we’re really talking about how many switches it contains. So, an 8-bit gaming system had 8 switches for graphics. Your 16-gigabyte hard drive holds 137,438,953,472 bits of information. Your phone is more powerful than the computers used by scientists in the 1980s.

See for yourself: http://www.youtube.com/watch?v=Dnd28lQHquU

#### Explore More

Watch the video below for a look into the history of video game consoles through commercials from the 1970s and 80s. Then answer the following question.

http://www.youtube.com/watch?v=lyVliqKJHsg

How were video game systems different when they had less memory?