võrdusmärke

Võrdusmärk is the Estonian word for the equals sign, represented by the symbol "=". It is a fundamental symbol in mathematics and logic, signifying equality between two expressions or quantities. The võrdusmärk indicates that the expression on its left side has the same value or represents the same mathematical object as the expression on its right side.

The concept of equality predates the symbol itself. Historically, various phrases and notations were used to express equivalence. The modern võrdusmärk, as we know it today, was first introduced by the Welsh mathematician Robert Recorde in his 1557 book *The Whetstone of Witte*. He chose two parallel horizontal lines because, in his words, "noe2 thinges can be moare equalle."

In mathematics, the võrdusmärk is crucial for defining variables, stating equations, and expressing identities. For example, in the equation 2 + 2 = 4, the võrdusmärk asserts that the sum of two and two is equivalent to the number four. In programming languages, a single võrdusmärk is often used for assignment, where a value is given to a variable, while a double võrdusmärk (==) typically represents a comparison for equality. The võrdusmärk is a universal symbol, understood across different languages and cultures within the realm of mathematics and science.