why do we use engineering notation instead of scientific notation
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".
Date and time notation in the United States In the United States, dates are traditionally written in the "month-day-year" order, with neither increasing nor decreasing order of significance. This order is used in both the traditional all-numeric date (e.g., "1/21/18" or "01/21/2018") as well as in the expanded form (e.g., "January 21, 2016"â€”usually spoken with the year as a cardinal number and the day as an ordinal number, e.g., "January twenty-first, two thousand sixteen"), with the historical rationale that the year was often of lesser importance. The most commonly used separator in the all-numeric form is the slash (/), although the hyphen (-) and period (.) have also emerged in the all-numeric format recently due to globalization.