Part of Lesson Plan: Binary 1- Calm Down, It's Only Ones and Zeroes- How Computers Think.
Activity Overview / Details
A vinyl record
Masking tape/ scotch tape
Paper to make a cone
Arrange the students into groups of 2 or 3. Have each student take out a sheet of paper and start a lab write-up titled “11 Cheers for Digital! Lab Write-up” with their name and other information in the upper right corner.
Give each group a vinyl record, preferably a 78. (78 records are stronger and have deeper grooves, so they work better for this lab).
Have them take a pencil or wooden dowel and put it tightly into the hole in the middle of the record. If the pencil does not fit tightly, wrap a little masking tape around it until it does.
Give them a piece of paper and have them roll it into a pointed cone and tape it together. Tape a needle or pin into the point of the cone so it sticks out a half inch or so.
Have one student place the tip of the pencil on the table and rotate the record slowly. Then have another student hold the top edge of the cone loosely and drop the needle gently in the groove of the record until they can hear a sound. Have them try different speeds and directions until they can get passable music out of their “record player”.
On their lab sheets, have the students write a brief summary of how the paper “record player” works.
Ask the students how easy or difficult it would be to assign a number value to the music at any given point.
Now have the students return to their seats. As they are sitting in their seats, turn the lights off. Ask whether the light is off or on. Now turn the light back on and ask the same question. Repeat several times, and then ask if there was any question as to whether the light was on or off. Explain that this is how digital information works, and how computers need information in digital form so there will be no question what a certain number is.
Now have a student clap with a slow, steady beat. Turn the light off and on and have the students write a “1” or “0” on their paper for every clap, a “1” if the light is on and a “0” when the light is off at the clap. Stop the clapping and have them look at their paper. Tell them that this is what a computer sees- just a series of “1”s and “0”s.
Explain to the students how computers send information as “ square waves” where a “1” is a pulse of electricity and a “0” is no electricity. Draw and example of a square wave on the board. Have the students draw a square wave like a computer might see just below the line of ones and zeroes they just created.
Explain that this is how computers create information, by turning the electricity off and on, much like a light switch. This way, just like in the previous activity, the computer can be sure it has the right information. Since computers only use two numbers, “1”and “0” (off and on), we call this system of seeing information “binary”. “Bi” means two, like a bicycle has two wheels.
Have the students write in their own words on the lab write-up why having computers use only ones and zeroes keeps them from making mistakes with numbers.