Making a Chinese Abacus

Objectives:

After learning about the history and the current uses of the abacus students will be able to produce their own.  When done students will have a contest against other groups and against students using calculators to see who can be the quickest.

Materials:

• Cigar Box

• Seven feet of bell wire

• 63 beads

• ruler

• hammer

• nail

• wire cutters

• stiff cardboard

Agenda:

Day one:  Students should be done with the first three steps after getting my OK after each step.

Day two:  Students should be done with the whole abacus after getting my OK after each step.

Warm-up:

Math problems (1)

• 10/01=

• 12/10=

• 14/10=

• 15/10=

• 17/10=

Measurement (2)

• measure the length of a pen

• measure the length of a book

• measure the length of the desk

• measure the length of a piece of paper

Instruction:

• Lay ruler along the length of the box, on the side where the lid is hinged.  Mark off ten evenly spaced divisions about one-half inch below the hinge with your pencil

• Using the hammer and nail, punch a hole right through each of the pencil marks you made on the box.

• Punch a second set of holes through the opposite side of the box, matching the first set exactly.

• Cut nine lengths of wire, thread the seven beads on each wire.

• Poke one end of the wire through one of the hole in the opposite side.

• Twist each wire tip sticking out of the box sides into sort of knot to keep the wire from slipping through the punched hole.

• Measure the length of the box exactly from the inner wall of one short side to the opposite wall, and cut an inch-wide strip of cardboard of that length.

• Lay strip across the wires in the box, and on it mark a little tick at each wire.  Cut slits to the depth of about one-half inch at each tick.

• Fit strip into box about one-third the distance from the hinged side to separate two beads from the remaining five of each wire.

 

Group Work:

Students will work in pairs 9or groups depending on availability of supplies).  After each step students will be required to double check their work and then pass it by me to make sure that they are on the right track.

Supplement:

When done, students can practice adding and subtracting using their abacus.

Evaluation: 

I will evaluate the students progress after each step.  The final assessment will be to see if the abacus works well.