# How to use an Abacus

Diagram of a typical Chinese abacus set to zero - all heaven beads pushed up and all earth bead pushed down.

## Try the on-line Abacus

The Abacus utilizes a combination of two bases (base-2 and base-5) to represent decimal numbers. It is held horizontally with the smaller deck at the top. Each bead on the top deck has the value 5 and each bead on the lower deck has the value 1. The beads are pushed towards the central crossbar to show numbers. Working from right to left, the first vertical line represents units, the next tens, the next hundreds and so on.

So for example to show the number 9, on the first line, one heaven bead (top deck) would be moved down (representing 5 units) and 4 earth beads (bottom deck) would be moved up (each representing 4 units). To show the number 79, in addition to the beads in the first line used to make the number 9, one heaven bead would be moved down and two earth beads would be moved up on the second line, representing 5 tens and 2 tens respectively.

Addition on the abacus involves registering the numbers on the beads in the straight-forward left-to-right sequence they are written down in. As long as the digits are placed correctly, and the carry

### Response to How to use an Abacus

1. On 01-Oct-2012, Anonymous wrote: To Reply Anonymous
Just to clarify; when using the abacus does one start from the far right side of the abacus or the far left side? Thank you.
• On 01-Oct-2012, Peter Tong replied:
Always from the far right.

2. On 19-Sep-2012, Anonymous wrote: To Reply Anonymous
thx very much i never really fully comprehend it but now i do

3. On 13-Sep-2012, Sabrine wrote: To Reply Sabrine
This information was very useful because it explained how to use a Abacus. so thanx
!

4. On 11-Sep-2012, Bryan wrote: To Reply Bryan
i need to know how to add or subtract or divide or multiply with an abacus!!! so this was no help. :(

5. On 22-Mar-2012, Israel wrote: To Reply Israel
just go to you tube if you don´t understand.they will teach you the technique.
• On 23-Jul-2012, Anonymous replied: Typo Error? Edit your message:
but its very nakakalito...

6. On 28-Jun-2012, SAIRA KHAN wrote: To Reply SAIRA KHAN
HELLO

you have shown working of abacus by table which is difficult to understand.

• On 23-Jul-2012, Anonymous replied: Typo Error? Edit your message:
your right its difficult to learn how to use abacus.....hehehehehe

7. On 26-Feb-2012, Miranda Fields wrote: To Reply Miranda Fields
Finally! A website that can clear things up for me. I spent 2 hours searching for someone that can help me and now I have it! I think I will get an A+ on this project. I´m recommending this to everyone in my fifth hour.
THANK YOU SO MUCH!!!

8. On 26-Sep-2011, Kevin wrote: To Reply Kevin
Thanks for sharing your inisight, I bought one at a garage sale and I´m excited to learn this Abacus.

Kevin

9. On 19-May-2011, Toon Van Dijk wrote: To Reply Toon Van Dijk