How To Use An Abacus
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William Gordon John Hope Academy
5515 S. Lowe
Chicago, Illinois 60621
The students will be able to:
1. Demonstrate the properties and operations of a number system
2. Develop an understanding of the commutative, associative and
distributive properties of the mechanics of the abacus
3. To understand the place value of whole numbers using an abacus
Chinese Abacus (Suan Pan or Soo Pain)
A typical Chinese abacus consists of columns of beads. A crossbar separates
the beads. Each column has two beads above the crossbar and five beads below
it. Each upper bead represents five units and each lower bead equals one unit.
The first column on the right is the ones' column; the second column is the
tens' column; the third column is the hundreds'; the fourth column is the
thousands'; and so on. The ones' column represents numbers from one to nine.
Each bead below the crossbar has a value of one (1) and each bead above the
crossbar has a value of five ones (5). The tens' column represents numbers from
10 to 90. Each bead below the crossbar has a value of ten (10). The beads
above the crossbar has a value of fifty (50). The hundreds' column represents
numbers from 100 to 900. Each lower bead equals 1 hundred (100) and each upper
bead equals 5 hundred (500).
To place a number on the abacus, move beads to the crossbar. When beads are
moved away from the crossbar, they are cancelled. This means a lower bead is
cancelled when it is lowered from the crossbar and an upper bead is cancelled
when it is raised from the crossbar.
To place the number 3,684 on the abacus, raise 3 of the lower beads in the
thousands' column. Then lower one upper bead and raise one lower bead in the
hundreds' column to represent 6 hundreds. Next, lower one upper bead and raise
three lower beads in the tens' column to show the 8 tens. Finally, in the
ones' column, raise four lower beads for the 4 ones. Now the abacus shows