Setting and Clearing Numbers

 

When computing using the Cranmer abacus "setting" and "clearing" are essential.  To set, the user moves a bead(s) to the horizontal bar.  When clearing the user moves the bead(s) away from the horizontal bar.  When teaching beginning abacus users, teachers begin by showing them how to set and clear numbers. It is important to clear the abacus before setting the next number. The pictures below show the proper finger position for setting and clearing using the Cranmer abacus.

Setting: The user pushes bead(s) below the horizontal bar using the thumb and the bead above the horizontal bar using the index finger.  The user is setting the number 8 in the photo below.

The user's index finger is pushing the 5 bead in the units column to the horizontal bar and 3 beads in the units column to the horizontal bar with the thumb.  The user is setting the number 8.

Clearing: Beads both above and below the horizontal bar are cleared using the index finger.  The photo shows clearing the three beads with value of 1 each that were set in the ones column.

The user is clearing the three 1-beads in the unit's column with the index finger.  

Download the PowerPoint show "Abacus Setting Numbers" from the file list below.  Click through each slide to practice setting numbers.  If you get 5 out of 5 correct on the quiz at the end of the presentation, you've mastered setting numbers.