In many cases, the ordinary equality symbol (=) is used in situations where, to be rigorous, the approximate equality sign ought to be used. Unicode Character (U+2248) Script: Code for undetermined script (Zyyy) Category: Math Symbol (Sm) Bidirectional Class: Other Neutral (ON) Combining. Almost Equal To: Unicode Version: 1. Or we might say that the speed S of a computer-file download is approximately 38.3 kilobit s per second (kbits/sec) we would then write S 38.3 kbits/sec. We might say, for example, that an incandescent lamp consumes a power P of approximately 60 watt s (60 W) then we can write P 60 W. In experimental physics and engineering, approximate equality is the rule, because measurements of physical quantities and phenomena are seldom exact. An example of an approximate equation using variables is x + y z. It is possible to express it to many more significant digits, but the result will always be an approximation. Expressed to four significant digits, 2 1/2 1.414. This is an irrational number when written in decimal form, it is nonterminating and nonrepeating. Approximate equality is symbolized by a squiggly equal sign ( ).Īs an example of how approximate equality can be used in mathematics, consider the positive square root of 2 (or 2 1/2 ). Two quantities are approximately equal when they are close enough in value so the difference is inconsequential in practical terms. Approximate equality is a concept used primarily in physics and engineering, and also occasionally in mathematics.