### Calculator Apps that Add Up

The standalone calculator in the classroom may become superfluous with a slew of high-quality, calculator apps available that can run on a phone or tablet. After all, who wants to spend thousands of dollars on a classroom full of slates only to also have to buy calculators for teachers and students.

The best part is that most of the calculator apps are free. The bonus is that any of these six apps can give you the right answer, but only if you ask the right question.

One of the most sophisticated calculator apps available, it’s a wonder that MathLab Mobile is a freebee. Available as a download on Google’s Play Store, it works with Android tablets and phones, but not iPads. It can replace handheld calculators with an array of high-end abilities, but is meant more for high-schoolers than younger students.

It does the basics well with the arithmetic and trigonometric functions, but MathLab’s repertoire includes everything from plotting multiple equations on a single graph to dealing with roots and slopes. The system can work with polynomial equations, fractions and matrices. The free version requires an Web connection and shows ads, but the $5.99 Pro version is ad-free and adds a handy library of constants and functions.

No matter how carefully you look you won’t find even the most rudimentary calculator on an iPad. That’s where Graphing Calculator 3D comes in. It not only works with all iPads and iPhones with iOS 5.0 or higher, but mimics the inputs for TI 80-series calculators. Its forte is the ability to show beautiful 3-D graphs of functions.

It’s a lot more than a pretty picture. In addition to computing permutations, factorials and the norm value, the app can move in and out of a graph as well as paste it into another app. Plus, when you’re done, the result can be emailed, a perfect way to submit homework assignments. The app is available at the iTunes Apps store for 99 cents.

JMT Apps Scientific Calculator

If you don’t want or need graphing, JMT’s Scientific Calculator does the trick with a deep library of abilities and math functions. It can not only be set up for traditional input or RPN operations, the Scientific Calculator lives up to its name with a built-in table of physical constants that will come in handy in the physics or chemistry lab.

It can hold ten different items in its memory and deal with fractions, basic math and trig functions as well as perform custom unit conversions. The Scientific Calculator keeps a running record of its calculations to go back and look for an error. It can work out permutations and combinations for statistics problems and perform modulus functions. As good as it is, the software is free for the download from the Google Play store.

If you’re looking for a slate calculator that’s easy to use and understand, Algeo’s Graphing Calculator is the one to get. It can carry middle- or high-schoolers through graduation and get them ready for college math. In addition to handling Taylor series, definite integrals and the basics of arithmetic, the Graphing Calculator can work with trig functions and hyperbolic equations. The software is can work in degrees or radians as well as scientific notation.

With its large screen-based keys and area up top to display the current calculation, Algeo’s calculator shows it all. It’s free and ready to be downloaded, but shows ads, sometimes in an intrusive manner.

Even if you have TI calculators, you can do calculations in software with TI’s N-Spire iPad app. There’s no Android software, but the latest version (3.8.1) goes beyond mere calculations to become a full math education program. It comes in two versions: N-Spire and CAS.

In addition to the expected data entry, graphing and statistical modeling, the TI app lets you work with inequalities, differential equations and conic sections. At any time you can take a photo with the iPad’s camera and overlay a graph or function on it to visually teach a math lesson about the slope of a roof or trajectory of a basketball. Aimed at classrooms from pre-algebra to Calculus and statistics, the software should carry a middle school math student through graduation and into college.

A big bonus is that anything your can work on can be emailed or send to a student’s or teacher’s Dropbox account, a good way to share assignments or homework. There are several built-in lessons as well as a vast online library for sharing lessons or techniques. On the downside, the software is expensive at $30 per tablet.

It’s not software in the traditional sense, but the Wolfram Alpha Web site is a quick way to figure out anything from a polynomial to a complex fraction. Just type in your equation or question and Alpha treats it like a PhD thesis topic, attacking it from multiple mathematical angles. For some there are solutions, graphs, visual manipulatives and even a calculus-based examination of the problem.

Alpha is a free Web site that every math class should visit and can be the basis of group projects. While the others return solutions in less than a second, Alpha can take a few seconds for it to formulate the answer and send it over the sometimes congested Web. There are unobtrusive ads for other Wolfram products, including its Differentiation and Integration calculators, two must-use pages for those classes. The Web page can be set up in several different colors and Alpha has the bonus of occasional pop-ups that ask math-related questions.