what is the symbol for parts per thousand
Per mille A per mille[1][2][3] (from Latin per mÄ«lle, "in each thousand"[4]), also spelled per mil,[1][2][4][5][6][7][excessive citations] per mill,[4][5][6][7][8][9][excessive citations] permil,[4] permill,[4] or permille[3] is a sign indicating parts per thousand. Per mil should not be confused with parts per million (ppm).
Scientific notation Engineering notation (often named "ENG" display mode on scientific calculators) differs from normalized scientific notation in that the exponent n is restricted to multiples of 3. Consequently, the absolute value of m is in the range 1 ≤ |m| < 1000, rather than 1 ≤ |m| < 10. Though similar in concept, engineering notation is rarely called scientific notation. Engineering notation allows the numbers to explicitly match their corresponding SI prefixes, which facilitates reading and oral communication. For example, 6992125000000000000♠12.5×10−9 m can be read as "twelve-point-five nanometers" and written as 6992125000000000000♠12.5 nm, while its scientific notation equivalent 6992125000000000000♠1.25×10−8 m would likely be read out as "one-point-two-five times ten-to-the-negative-eight meters".