With the four-bead abacus spread, it is also common to use Japanese abacus around the world.

The most popular abacuses are the roman abacus and the Chinese abacus suan pan.

That means that $abacus and @abacus are two different variables, and $abacus[0] (the first element of @abacus) is not the same as $abacus{0} (the value in %abacus that has the key 0).

The multipurpose abacus of the present invention includes an abacus frame, which is closed at the bottom thereof and has upper, lower, left and right frame walls (10), (30), (20), (40).

That means that $abacus and @abacus are two different variables, and $abacus[0] (the first element of @abacus) is not the same as $abacus{0} (the value in abacus that has the key 0).

In addition to well-known accounting frames, there were other devices for calculations: for example, this round mechanical calculator called Optima, which was released around 1900 in Germany.

The abacus , also called a counting frame, is a calculating tool that was in use centuries before the adoption of the written modern numeral system and is still widely used by merchants, traders and...

The abacus, also called a counting frame, is a calculating tool that was in use centuries before the adoption of the written modern numeral system and is still widely used by bankers, merchants and traders world over.

The abacus (plural abaci or abacuses), also called a counting frame, is a calculating tool that was in use in the ancient Near East, Europe, China, and Russia, centuries before the adoption of the written Hindu–Arabic numeral system.

The abacus, also called a counting frame, is a calculating tool that was in use in Europe, China and Russia, centuries before the adoption of the written Hindu-Arabic numeral system.