Binary Post-Its
Warning! Obligatory number system description ahead.
While we convert numbers based on a decimal system, computers use a binary system, understanding ons and offs as numbers.
Decimal (base ten): If you add one to nine, you have to carry, and you get ten.
Binary (base two): If you add one to one in binary, you have to carry, and you get ten.
Binary conversion works with liquid measurement: one cup + one cup = one pint; one pint + one pint = one quart; one quart + one quart = one half gallon. Think of one cup as 1, two cups (a pint) as 10, three cups (a pint and a cup) as 11, four cups (one quart) as 100, and so on.
Easy enough. What if you had a byte of information to convert, though, something that looked like this?
10101010
Obligatory number system description off.
It's time to bring out the Post-its and Popsicle sticks.
While we convert numbers based on a decimal system, computers use a binary system, understanding ons and offs as numbers.
Decimal (base ten): If you add one to nine, you have to carry, and you get ten.
Binary (base two): If you add one to one in binary, you have to carry, and you get ten.
Binary conversion works with liquid measurement: one cup + one cup = one pint; one pint + one pint = one quart; one quart + one quart = one half gallon. Think of one cup as 1, two cups (a pint) as 10, three cups (a pint and a cup) as 11, four cups (one quart) as 100, and so on.
Easy enough. What if you had a byte of information to convert, though, something that looked like this?
10101010
Obligatory number system description off.
It's time to bring out the Post-its and Popsicle sticks.
Tools and Materials
A pad of notes
8 sticks
Glue or glue stick
Highlighter (or any marker that doesn't bleed through the notes)
8 sticks
Glue or glue stick
Highlighter (or any marker that doesn't bleed through the notes)
Make Your Ones and Zeros Flip
Take a stack of two notes. On the top write a zero, then fold it in half and write a one.
I liked constructing it this way because it reminded me of those old digital flip clocks.
I liked constructing it this way because it reminded me of those old digital flip clocks.
Line Up Your Binary Numbers
Make a column of eight ones and zeros.
Line Up Your Decimal Numbers
Make a matching column of decimal-based numbers. These will be your powers of two:
- 20 = 1
- 21 = 2
- 22 = 4
- 23 = 8
- 24 = 16
- 25 = 32
- 26 = 64
- 27 = 128
Make 'em Flip
Glue and apply sticks to the bottom of the notes when set to "0".
Start Converting
Set your binary number. Move the stick to the bottom for "0", or low, and to the top for "1", or high (If you were a computer, you'd be feeling some voltage).
Add all the decimal numbers on the right. You can use a note on the bottom to do your sums.
So what about that number: 10101010?
That's 128 + 32 + 8 + 2.
Binary 10101010 = decimal 170.
Have fun flipping.
Add all the decimal numbers on the right. You can use a note on the bottom to do your sums.
So what about that number: 10101010?
That's 128 + 32 + 8 + 2.
Binary 10101010 = decimal 170.
Have fun flipping.
Variations, Improvisations, and Meditations
How about a hinged wooden version that goes clackety-clack, or a flipping byte converter run by a micro-controller?
Coffee stirrers actually work much better than Popsicle sticks. As you can see, I wrote a note at the top. What kind of notes would you write? Would you put a white board or black board at the bottom? How would the flipping converter work four bits at a time? What would an octal or hexadecimal converter look like?
Coffee stirrers actually work much better than Popsicle sticks. As you can see, I wrote a note at the top. What kind of notes would you write? Would you put a white board or black board at the bottom? How would the flipping converter work four bits at a time? What would an octal or hexadecimal converter look like?