HP Prime
The HP Prime is a graphing calculator manufactured by Hewlett-Packard (HP). It contains features common in smartphones, with a touchscreen and apps available to put onto it. There are two sides to the calculator, a numeric home screen and a computer algebra system (CAS) homescreen. The calculator can quickly switch between the two, unlike its competitors, which either have a CAS model or a non-CAS model. The CAS is based on the free and open-source Xcas/Giac 1.1.2 engine by Bernard Parisse, who was also the main developer of the CAS system integrated into the HP 49G and successors. The calculator has a 1500 mAh battery, which is expected to last up to 15 hours on a single charge. Prime emulator PC software is available as well.
It has also, for now (2015), taken the title for the world's smallest CAS calculator at 18,23×8,58 cm and is also the thinnest CAS calculator available currently, with a thickness of only 1.39 cm.
Exam Mode
The HP Prime has a novel feature called Exam Mode. This enables various features of the calculator (such as CAS functionality, user-created apps, notes, etc.) to be selectively disabled for a specific time, from 15 minutes to 8 hours. This can be done manually within the calculator's menus, or by using a computer with HP's connectivity software. LEDs on the top of the calculator blink to let the instructor see that the calculator is in this mode. Despite this feature, the Prime is still prohibited in many examinations, such as the US's ACT college-entry test. It is however starting to be accepted in other examinations, like those run by the Dutch CvTE, the Swiss IB, or Alberta (Canada) education authorities.
Prime number
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example, 5 is prime because 1 and 5 are its only positive integer factors, whereas 6 is composite because it has the divisors 2 and 3 in addition to 1 and 6. The fundamental theorem of arithmetic establishes the central role of primes in number theory: any integer greater than 1 can be expressed as a product of primes that is unique up to ordering. The uniqueness in this theorem requires excluding 1 as a prime because one can include arbitrarily many instances of 1 in any factorization, e.g., 3, 1 · 3, 1 · 1 · 3, etc. are all valid factorizations of 3.
The property of being prime (or not) is called primality. A simple but slow method of verifying the primality of a given number n is known as trial division. It consists of testing whether n is a multiple of any integer between 2 and 
. Algorithms much more efficient than trial division have been devised to test the primality of large numbers. These include the Miller–Rabin primality test, which is fast but has a small probability of error, and the AKS primality test, which always produces the correct answer in polynomial time but is too slow to be practical. Particularly fast methods are available for numbers of special forms, such as Mersenne numbers. As of January 2016, the largest known prime number has 22,338,618 decimal digits.
Prime (liturgy)
Prime, or the First Hour, is a fixed time of prayer of the traditional Divine Office (Canonical Hours), said at the first hour of daylight (approximately 7:00 a.m.), between the morning Hour of Lauds and the 9 a.m. Hour of Terce. It is part of the Christian liturgies of Eastern Christianity, but in the Latin Rite it was suppressed by the liturgical reforms following the Second Vatican Council. However, clergy who have an obligation to celebrate the Liturgy of the Hours may still fulfil their obligation by using the Roman Breviary promulgated by Pope John XXIII in 1962, which contains the Hour of Prime. Like all the liturgical hours, except the Office of Readings, it consists primarily of Psalms. It is one of the Little Hours.
Name
The word "Prime" comes from Latin and refers to the first hour of daylight (i.e., dawn). Originally, in the West, Prime was called matitutina (hora), "morning hour". Later, in order to distinguish it from the nocturnal offices of Matins and Lauds, and to include it among hours of the day, it was called prima. The name is first met with in the Rule of St. Benedict. In the Antiphonary of Bangor it is called secunda.
Prime (film)
Prime is a 2005 American romantic comedy film starring Uma Thurman, Meryl Streep and Bryan Greenberg. It was written and directed by Ben Younger. The film grossed $67,937,503 worldwide.
Plot
Rafi (Uma Thurman) is a recently divorced, 37-year-old career woman from Manhattan who becomes romantically involved with David (Bryan Greenberg), a talented 23-year-old Jewish painter from the Upper West Side. Rafi shares all her secrets with her therapist Lisa (Meryl Streep) who, unbeknownst to Rafi, is David's mother. Lisa, supportive of Rafi's relationship with a younger man, discovers the connection and finds herself not only faced with the ethical and moral dilemma of counseling David's girlfriend, but also the reality that she feels differently about the relationship now that she knows her son is involved. Lisa consults her own therapist, and they decide that it is in the best interest of her patient Rafi for Lisa to continue treatment, as long as the relationship remains the "fling" it appears to be.
