10-4 is one of the so-called ten-codes, or radio signals, invented by the Association of Public-Safety Communications Officials-International (APCO). 10-4 is an affirmative signal: it means “OK.” The ten-codes are credited to Illinois State Police Communications Director Charles Hopper who created them between 1937–40 for use in radio communications among cops.
Algebra. Evaluate log of 10^-4. log(10−4) log ( 10 - 4) Use logarithm rules to move −4 - 4 out of the exponent. −4log(10) - 4 log ( 10) Logarithm base 10 10 of 10 10 is 1 1. −4⋅1 - 4 ⋅ 1. Multiply −4 - 4 by 1 1. −4 - 4.
Ten-codes, especially "10-4" (meaning "understood") first reached public recognition in the mid- to late-1950s through the popular television series Highway Patrol, with Broderick Crawford. [ citation needed ] Crawford would reach into his patrol car to use the microphone to answer a call and precede his response with "10-4".
10-4 means "OK," "understood," and "affirmative." Commonly known as CB radio lingo, originating from the need for brevity in radio transmission.
As for the Ten Codes, and why 10-10 means, "I'm done," and 10-4 means "I heard you," rather than the other way around, I'm not sure there's any particular reason. Maybe there is a reason, but that reason is closely guarded 10-35 (confidential information). According to Wikipedia, CB is still in use today:
Numerology. Chaldean Numerology. The numerical value of 10-4 in Chaldean Numerology is: 0. Pythagorean Numerology. The numerical value of 10-4 in Pythagorean Numerology is: 0.
OK; all right. Used to indicate affirmation or acknowledgment. The phrase comes from CB radio, which was commonly used (especially by truck drivers) before the proliferation of cell phones. A: "I'm going to pull over up ahead." B: "10-4." Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
One of the most frequently used ten-codes, 10-4, has become popular enough to sometimes be used in every-day language. Code. Description. 10-00. Officer down, all patrols respond. 10-0. Use caution. 10-1. You are being received poorly / Cannot copy.
“10-4” is a shorthand code. Why are these so useful? As mentioned in the introduction, 10-4 is an example of a shorthand code. But why do the police like to use these? The main reason is that it’s easier and quicker to communicate this way. Police radios aren’t used for listening to music; the quality of the sound doesn’t matter all that much.