CSE*xplore*

*Where Your Future Computes!*

What is an Abacus

The Abacus is one of the first counting tools. It was used centuries before the modern number system was even invented. It is technically the first computer. A computer is a device that stores and processes data. Data is the raw value that becomes information when meaning is given to the data.

Activity

You will be building your own binary abacus using popsicle sticks, beads, and pipe cleaners.

You will use pipecleaners to hold the counting beads together in a popsicle stick-frame. The top pipe cleaner has 1 bead, that is the digit on the right part of the number, just like the 1’s place in decimal, this is also 20. The next position to the left in decimal is the 10’s place, that each value is 10 times that value, in binary you have 2 beads, so you either have a value of 2 or zero coming from that spot, this is also 21. The next spot to the left is the 100’s place in decimal, in binary this place is worth zero or 4, this is also 22.

This pattern will continue as you add more values to the left, with the value you get from that spot doubling with each position. Once you know your values from every position in the number, you add them together, just like you would in decimal. A picture of what your binary abacus will look like is depicted below

Materials

- 6 popsicle sticks
- 15 beads
- 4 pipe cleaners
- Tape

Directions

- Take four popsicle sticks and connect them with tape in the corners to make a square
- Overlap two sticks
- Take a piece of tape about 2 inches long
- On an angle going inward, put the tape on top of the first stick
- Then wrap the tape underneath, connecting it to the second stick in the corner
- Continue to wrap the tape around to use the rest of the initial amount
- If needed, wrap with more tape.
- Repeat for the rest of the corners

- Get 4 pipe cleaners
- Insert beads into the pipe cleaners. The first pipe cleaner should have one bead, the second pipe cleaner should have two beads, the third pipe cleaner should have four beads, and the last pipe cleaner should have eight beads.
- Lay the pipe cleaners with the beads across the box you made in step 1 lay the pipe cleaners with the beads across the popsicle sticks and tape the ends to the popsicle stick.
- Get two more popsicle sticks and place them on top of the sides with the pipe cleaners connected and tape those in the corners as you did with the first step.
- On the left side of your abacus, write “0’s” down the popsicle stick. The right side of your abacus should have “1’s” down the popsicle stick.