Addition by Grouping


Direct Addition

Direct addition can take place when a digit needs to added and all of the beads are available. One motion of your hand will complete the addition. Click on the link, Direct Addition, to learn this skill.

Direct Subtraction

To directly subtract a number or a digit in a number, the all the beads need to be present in the column. Click on the link, Direct Subtraction to learn this skill.

Adding with Five Extras

The first basic lesson you should learn is how to add a number to a column when all the beads below the bar have been pushed to the bar. We call this Adding with Five Extras since it involves using the 5 bead. Click on this link above to study this technique in detail.

Subtracting with Five Extras

It may seem strange to have a Subtraction section in the middle of an Addition page. However, it will be time well spent to study Subtraction with Five Extras before you continue to the next section, Adding with Ten Extras. Click on the link above to start the lesson.

Adding with Ten Extras

Using the skill that you have developed in adding and subtracting using Five Extras, you are now ready to learn how to subtract a number to a column where all of the beads are set (shows the number 9). This technique is called Adding with Ten Extras. Click on the link to start the lesson.

Adding with Five Extras and Ten Extras

Now you are ready to subtract any whole numbers of any size using Direct Subtraction, Five Extras, and Ten Extras. Click on the link, Adding with Five Extras and Ten Extras to continue developing your abacus subtraction skills.

Adding Decimals and Columns of Decimals

Lastly, you can put your addition skills to work, subtracting decimals and columns of decimals. Click on the link, Adding Decimals and Columns of Decimals to complete the addition lessons.

Abacus Addition by Grouping Text

You can view the full text of this material by clicking on the link, Abacus Addition by Grouping.