# HP Calculators

## HP Prime Graphing Calculator Review

# HP Prime Review

HP’s answer the TI Nspire CX CAS is finally here and now its time to see how this color graphing calculator stands up to the competition.

With the new HP Prime the creators set out to create a 21st century calculator that blows the competition out of the water while appealing to the widest audience possible and they have done just that!

Breaking from tradition the Prime supports both Reverse Polish Notation and algebraic notation, which opens this calculator up to a whole new generation of users who are uncomfortable using RPN.

## Overview

Full color-screen, wireless connectivity, with multi-touch capability, 2300 installed functions and support for both algebraic and reverse Polish notation.

## Specs

- 256mg flash memory
- 32mb mDDR ram
- 400mhz ARM9 processor
- Rechargeable lithium battery
- USB port
- 320×240 16 bit color touch screen

>>> Click here to see ratings, reviews, specifications and prices on Amazon < < <

## Pros

- Speed. The 400mhz processor is blazing fast, with the calculator giving almost instantaneous results.
- Backlit color touch screen. Navigates similar to a smart phone. No more time consuming scrolling with buttons.
- RPN and Algebraic notation support.
- Robust support for app developers and users.

## Cons

- Keys are a bit on the small side.
- Lack of an expansion slot.
- Manual comes on cd, not a printed book.

## Bottom Line

The HP Prime is one of the best graphing calculators currently on the market. Its blazing fast speed, easy to use touch screen, and large number of available apps make this calculator an easy choice for those looking for a modern, powerful calculator.

>>> Click here to see ratings, reviews, specifications and prices on Amazon < < <

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## Hp 15C Limited Edition Scientific Calculator Review

# Hp 15C Limited Edition Review

The HP 15C Limited Edition was released on the 30^{th} Anniversary of Hp-12C edition. The earlier version (HP 15C Scientific Calculator) was introduced in the market in 1982 but it was discontinued in 1989 and the price of that scientific calculator was about $100. The latest version of Hp-15C i.e. HP 15C Limited Edition was released in 2011 and its price was about $180. The Hp-15C Limited Edition is the latest version of HP 15C Scientific Calculator with the modern ARM technology which is powered by 12C hardware. This new version is very practicle for the power users, providing portability and it provides RPN mode which makes the computation easier. This version is more advantageous to engineers as it provides the complex computation operations like complex numbers, matrix operations, integration, differentiation and roots problems. The new version of the HP-15cis better than its original version in many respects i.e. the design of HP 15C Limited Edition is more simple and elegant, it provides more scientific functions, it is portable as it can be placed in the pocket of a shirt and its keyboard keys are less solid and are user friendly.

The Limited Editionis much faster than the original Hp-15C as it provides the answers of the complex problems like integration of polynomial functions and factorial of non-integers in the glimpse of an eye. HP has provided about one hundred times faster operations than the original Hp-15C edition. The palpable response of the keys of the Limited Edition is another big achievement of Hewlett Packard. The re-released version has a detailed manual about using the calculator for the desired calculations, a sleek and attractive collectible box and a CD for the instructions. The display of the Limited Edition is also better than the original one as it provides a wider display range and better contrast. The processor is much faster and the operating system starts up and shuts down instantly. To sum up the whole story, the Limited Edition is better than the original version in all respects. If you want a fast computations, a large display, palpable response of the keys, portability of the calculator, a scientific calculator with all the functions needed for the engineers and scientists then don’t wait prices are rising fast on the Limited edition as the short supply is gobbled up by die hard HP collectors itching for a chance to own the new HP 15C Limited Edition.

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## Reverse Polish Notation Calculator – RPN Vs Algebraic Calculator

Reverse Polish Notation is also known as “postfix notation”. It is named so because in this notation all the operands are placed before the operator. This notation is also of interest because no parenthesis is used in RPN notation. A Polish logician and philosopher Jan Lukasiewicz invented prefix notation in 1920s; that’s why the word “Polish” has been placed in the title of this notation. Burks, Warren and Wright were the people who were involved in introducing Reverse Polish Notation scheme in 1954. There was further development in the algorithms of RPN in the mid of 1950s by Charles Hamblin. RPN scheme was known to many calculator users during 1970s and 1980s. Hewlett Packard used Reverse Polish Notation first time in the scientific calculator named 9100A in 1968.

While using the calculators with algebraic notations, the use of parenthesis is quite a big problem. The parenthesis does not matter a lot in simple calculations but they create much confusion while dealing with complex calculations. The BODMAS rule is applied while dealing with the mathematical calculations using algebraic notation but the BODMAS rule becomes very confusing when there are brackets in the mathematical expression and it becomes even more confusing when there are brackets inside the brackets. This mess can be solved by using calculators using Reverse Polish Notation in which the operators appear in the order which is required for the computation. In the calculators using RPN, complex calculations can be done quite easily by using a minimum number of special symbols.

One simple example can serve this purpose of showing that the calculators using RPN are better than the calculators using algebraic notation. Suppose we want to calculator “4+5×2” in such a way that we want that the operator “+” operates before “×” giving the result equal to “18” neglecting the BODMAS rule. This thing can only be done in the regular calculators using Algebraic notation by using a bracket across “4+5” so that the above expression takes the form as “(4+5)×2”. Now this will give the right answer as we want.

There are many reasons for using a RPN calculator rather than a calculator using algebraic notation. An RPN calculator saves time because the same calculation can be performed in less time as compared to a regular calculator. For example, we want to compute “(13+3)÷(4×2)” using a calculator of algebraic notation (not a scientific one) then we have to do many steps to reach the answer. Firstly, we have to compute “(13+3)” and then we will save the answer to the memory of the calculator. Then we have to compute the calculation in the denominator i.e. “(4×2)” and we have to save this answer too to the memory of the calculator. In the end, we will bring both the answers and will perform the last operation of division. This procedure has taken a reasonable amount of time. This thing can be avoided by using RPN calculator. In RPN calculator, we have to insert just a single line expression as “13 Enter 3 + 4 Enter 2 × ÷” and the answer will be computed instantly.

Reverse Polish Notation has stack which is absent in case of algebraic notation calculators. RPN operates in a way that if an operand appears next in the expression then the operand value is pushed on to the stack and if an operator appears next in the expression then two operand values from the top of the stack are popped and the answer of these values is pushed on to the stack. For example, if the expression “4+6+7” has to be computed then in RPN, it is inserted as “4 Enter 6 Enter 7 + +”. The value “4” is pushed on to the stack followed by the value “6” and then followed by “7” but after appearing the operator “+”, two values from top of the stack i.e. “7” and “6” are popped up and their result i.e. “13” is pushed on to the stack. After appearing the operator “+” in the expression again, two top values from the stack i.e. “13” and “4” are popped up and their result i.e. “17” is pushed to the stack. The other important feature of RPN is that we can go back to any place in the stack by using they key “R↓”.

The other reason of using RPN rather than algebraic notation is that RPN is less complicated. While doing the calculation like “12+8”, the answer of the calculation is not displayed on the screen until we press “=” or any other operator symbol. This thing is very confusing for the users because on pressing “+”, “-“, “×” or “÷” symbol, the respective operation must take place rather than giving the result of the previous calculation. RPN in more intelligent in this case. When “+” key is pressed in case of RPN then addition is performed always; that’s the case with subtraction, multiplication and division.

It is usually thought that algebraic calculations are taught in schools because they are easy to understand. The algebraic calculations are easy to be inserted in the calculator as we have just to read the mathematical expression from left to right and then inserting the expression in the calculator. But this thinking is absolutely wrong because algebraic calculations are easy to be done only in the case when we are inserting the mathematical expression into the calculator by reading from some source. But if we have to deal with the expressions which are made on the spot by mind then RPN is the best method because we don’t have to remember the calculation results in the intermediate steps to move ahead as in the case of algebraic calculations.

This thing can easily be done using RPN. In all the calculators using RPN, there is a key named “Enter”. This key is pressed every time when an operand is inserted in the expression to separate one operand from the other. While solving the mathematical expression “(4+5)×2” using RPN calculators, the expression is inserted as “2 Enter 4 Enter 5 + ×”. This will give the correct answer as “18”. Likewise if we want to calculate “4+(5×2)” then this expression is inserted in RPN calculator as “4 Enter 5 Enter 2 × +” and this will give the answer as “14”. This thing happens in the stack in the following way:

For Mathematical expression “(4+5)×2”

First Step (Initial State)T: 0Z: 0Y: 0
X: 0 |
Second Step (Press “2” then “ENTER”)T: 0Z: 0Y: 0
X: 2 |

Third Step (Press “4” then “Enter”)T: 0Z: 0Y: 2
X: 4 |
Fourth Step (Press “5” then “ENTER”)T: 0Z: 2Y: 4
X: 5 |

Fifth Step (Press “+” then ENTER)T: 0Z: 0Y: 2
X: 9 |
Sixth Step (Press”×” then ENTER)T: 0Z: 0Y: 0
X: 18 |

For Mathematical Expression “4+(5×2)”

First Step (Initial State)T: 0Z: 0Y: 0
X: 0 |
Second Step (Press “4” then “ENTER”)T: 0Z: 0Y: 0
X: 4 |

Third Step (Press “5” then “Enter”)T: 0Z: 0Y: 4
X: 5 |
Fourth Step (Press “2” then “ENTER”)T: 0Z: 4Y: 5
X: 2 |

Fifth Step (Press “×” then ENTER)T: 0Z: 0Y: 4
X: 10 |
Sixth Step (Press”+” then ENTER)T: 0Z: 0Y: 0
X: 14 |

HP 15C Scientific Calculator

is shown in the figure below. Hp-15c uses five registers in complex mode. There is an easy method to enter a complex number in Hp-15c. The real part of the complex number is entered by pressing “ENTER” and then the imaginary part of the complex number is entered by pressing “f1” key. By doing so, the real part of the complex number is displayed on screen and the imaginary part is saved to the stack. The user can see the imaginary part on the display of the calculator by pressing “f(i)”. In this way, the user can see both the imaginary and real parts of the complex number.

HP 15C Scientific Calculator

was the first model with Matric calculation. The calculations on this calculator can be done with 5 matrices which are named as A, B, C, D and E. There is a very easy way to set the dimensions of the matrix on this calculator. The user has to enter the expression “2 Enter 2 fDIM A” for defining matrix A as 2 by 2 matrix. The user can insert the elements of the matrix explicitly by adjusting the rows and the columns. The size of the matrix as defined by the user can be shown by the expression “RCL MATRIX A” and the result will be displayed on screen as “2 2”. This calculator has the capacity for storing 64 matrix elements. Many of the matrix functions can be performed on this calculator like determinants, LU Decomposition, Inverse of the matrix, multiplication, addition, subtraction etc.

By looking at all the factors discussed so far, it is proved that RPN is much better than the regular algebraic calculation because RPN saves time; the calculations can be done with less number of keystrokes; RPN has stack; there is no need of parentheses in case of RPN; RPN is more intelligent; RPN is elegant and RPN does the computation which matches the thinking of the user.

### Interested in reading more about reverse polish notation? Check out Algorithms for Reverse Polish Notation Calculators

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