abacus

UK /ˈæbəkəs/ US /ˈæbəkəs/ Syllables: ab-a-cus

Pronunciation

Noun A2 Elementary Neutral

A frame with sliding beads used for counting and simple arithmetic.

An abacus is a counting tool made of a frame with rods or wires and sliding beads. Each rod stands for a place value, such as ones, tens and hundreds, and moving the beads up and down is a way to add, subtract and do other sums. It is an ancient tool, and it is still used in some places today. The plural is abacuses or abaci, and both are correct. In architecture, abacus also means the flat slab at the top of a column. The word is a countable noun. A close term is counting frame. A calculator does the same job with electronics instead of beads.

"The shopkeeper still used an abacus to add up the total."

Meanings

A frame with sliding beads used for counting and simple arithmetic.
In architecture, the flat slab at the top of a column.

Example sentences

"The shop owner added the prices on an abacus."

Level A2, Meaning 1
"She learned to count with a small wooden abacus."

Level A2, Meaning 1
"An abacus has rows of beads on rods."

Level A2, Meaning 1
"The museum has two abaci from different centuries."

Level B2, Meaning 1
"The abacus sits at the top of the column."

Level C1, Meaning 2

Look-alikes and common mistakes

calculator : A calculator is an electronic device. An abacus is a frame with beads and needs no power.
abaci : Abaci is one correct plural of abacus. The other is abacuses.
slide rule : A slide rule is a ruler with a sliding part, used for multiplying and dividing. An abacus uses beads.

Word family and forms

Forms: abacuses, abaci

Word partners

Words and phrases that often go with "abacus".

a wooden abacus
an abacus frame
count on an abacus
abacus beads
a Chinese abacus
use an abacus
an abacus and a calculator

Origin

Abacus came into English in the 1300s from the Latin word abacus, which meant a board or table with a flat top, and also a counting board. The Latin word came from Greek abax, meaning a slab, a counting board or a board covered with sand for drawing. The plural abaci follows the Latin pattern.

Checked against: Wiktionary, the free dictionary, Dictionary.com.

How to remember it

Picture the beads clicking along the wires. Each bead you slide is one more in the count, and the frame that holds them is the abacus.

Test yourself

Which word fits the gap? "The shop owner added the prices on an _____."

Answer: abacus

In your own words, what does "abacus" mean?