Average Reviews:
(More customer reviews)The HP 20b is Hewlett Packard's new lower-end financial calculator. This machine is a very welcome addition to HP's financial calculator line. This calculator certainly exceeds the functionality of Texas Instrument's offerings in the financial calculator marketplace, which should make this a big seller, particularly in colleges. Remember that this product seems primarily designed to compete with TI's offerings.
The display. The HP 20b display provides a great deal of information. Numbers are displayed with a 12 digit mantissa and up to a 3 digit exponent. The range is from -499 to +499. Annunciators are in the top right area. The top row of the screen is where results are labeled with letters. HP has made this area of the screen that labels results scroll messages, which allows for messages longer than the 9 characters that fit into this box.
Three operating modes. For the first time, HP has three operating modes on a financial calculator: RPN, Algebraic and Chain mode. RPN is a very welcome addition. It has been a long time since HP offered RPN on a fairly low priced financial calculator. Sure, it has been available on the 12c, 12cp and 17bII+ models, but has been missing from the 10b/10bII lines. LastX is there too, labeled ANS as the shift of the = key. The HP 20b also has a double-wide I key that functions as ENTER when in RPN mode. HP also provided two welcome shortcuts for RPN users. The otherwise useless parentheses keys serve as roll down and X<>Y in RPN mode. A tiny little symbol in the bottom right corner indicates the shortcut function of the ( and ) keys. RPN is not an afterthought on the 20b.
Chain mode is what HP has used on their low end machine (10bII) for some time. This mode is algebraic without hierarchy such that 1+2x3= gives a 9 as an answer. The HP 20b has Chain mode but adds Algebraic mode. In Algebraic mode, fairly normal rules of algebraic hierarchy are followed, as you would expect. Parentheses can be used to alter the order of execution. The 20b can handle up to 12 pending operations.
Menus. The HP 20b takes a new approach to providing functionality compared to many former HP calculators. It is more similar to the 17bII+ in some ways than the 12c. Pressing one of 16 keys will open up a menu where you use a combination of the INPUT key and the UP and DOWN arrow keys to move between your choices. This approach has the benefit of greatly expanding the available features without adding an additional shift key. It is also a departure from the 32s, 32sII, 33s, 35s menu approach. The approach taken by the 20b is designed to be familiar to student financial calculator users, who probably have never seen or used one of these other models. This was a very defining characteristic of the 20b's design. It seems to be aimed at students who are used to the TI model. It is not meant to be a direct replacement for an existing HP model.
Bond and date calculations. The bond calculations are a welcome addition to the low-end financial calculator and include all the expected features, including call provisions. The date calculation menu provides some nice touches, such as working in either actual or 360-day calendar mode. It also indicates the day of the week.
Extended financial features. The 20b includes several extended cash flow analysis features compared to other financial calculators. In addition to the usual NPV and IRR, the 20b provides net future value, net uniform series, payback and discounted payback.
Scientific functions on a financial model. Well, not so much new as finally returned. For the first time since the HP 19bII calculator, HP has a financial model with functions such as these: trig and inverse trig in degrees or radians, and hyperbolic functions and inverses. At last! An HP financial model again with trigonometric functions! Why is this so important? It greatly reduces the need, particularly in college, to have two calculators. As a former college instructor, I can't tell you how many times people carried two calculators - one for their physics or chemistry class, the other for their business classes...all because their business calculators did not have trigonometry and other scientific functions. It is also very important to keep the functional comparisons level with the competitors, all of whom offer these functions on their business models.
The Probability functions in the MATH menu is a real gem. It includes FOUR common probability distributions and their inverses: the normal distribution, Student's t distribution, Chi-square distribution, and the F-distribution along with their inverses. This greatly increases the usefulness of the 20b for the student as well as professional.
Statistics functions too. Combinations and permutations are back, finally and on the keyboard. Without these, users had to manually compute them using the factorial function, which is certainly doable, but very manual. The factorial function computes the gamma function if given a real number. A random number generator is present as well. The other statistics functions work on data entered into the Data menu.
The DATA menu allows you to enter up to 50 pairs of statistics data. (Note: Memory is shared between the data and cashflow areas - the 20b has 50 slots for pairs of statistical or cashflow data in total). If you try to enter the STATS menu before you've entered any data, the 20b will enter the Data menu for you.
The Statistics menu contains a Descriptive sub-menu which provides two functions not seen on HP financial calculators before: standard error of the sample X and Y means, which are very useful for things such as hypothesis tests and confidence intervals. The Predictions sub-menu first asks you to choose a regression model. Six models are included:
Linear: a*X+b Logarithmic: a*LN(X)+b Power: b*X^a
Base e exponential: b*e^(aX) Base a exponential: b*a^X Inverse: a/X+b.
A somewhat hidden function is the BEST FIT function. When the regression model is displayed, pressing = causes the 20b to quickly fit all six models to the data and choose the model with the correlation whose value is closest to the absolute value of 1. The displayed regression model will be changed to the model that provides the best fit. If the display does not change, the model shown was the best already.
Other menus and features. In addition to loan amortizations, the 20b includes several depreciation methods other than the normal straight line, declining balance and sum-of-digits: it includes declining balance crossover and French straight line and an accelerated French method. The breakeven menu performs the calculations you would expect including solving for a target profit, i.e. a non-breakeven breakeven. The %calc menu is where the markup as a % of price and as a % of cost functions are found as well as part as a % of total and % change. The % change provides a useful extension by allowing for the number of periods to be specified before computing the % change, turning this into a quick compound growth rate computation if desired.
What else is interesting? The 20b provides a function no other financial calculator has ever provided built-in. When doing interest rate conversions, you can solve for any of these three if the other two are known: Effective rate, nominal rate or periods per year. Even on the venerable 17bII+, you can't solve for the number of periods per year unless you use the equation EffectiveRate = (1 + NominalRate
