SECTION THREE. MOVING THE COMPUTER ABACUS BEADS
To move a bead to the crosspiece, point to it and click on the mouse button. It will move up to the crosspiece and change color from with to blue. To move a bead away from the crosspiece, point to it and click the mouse button. It will move away from the crosspiece and change color from blue to white. See the diagrams below.
In all of the diagrams in this manual, an arrow will point to the result of the bead movements.
To move more than one bead at a time, point to the bottom bead (or top bead) and click on the mouse button. All beads in the column will move up to or away from the crosspiece and change color. See the diagrams below.
After the operating features of the abacus program are understood, use the following exercises to practice moving beads on the computer abacus.
Place the beads on the abacus in the proper order for the following numbers. (Remember, column 8 is normally used as the unit digit column.)
The following five sections explain complementary numbers and give the procedures for addition, subtraction, multiplication and division on the abacus.
You will see that the procedures are different from the way you have worked arithmetic problems in the past. It is important to train your mind to think in a different way when using the abacus. It may seem awkward at first but with practice you will find that your mental arithmetic skills are much improved.