Yes, the iPhone has a built-in calculator, and so does Android. But there are a number of third-party apps for both platforms that might be better suited for some problems; they support everything from basic math to algebra, calculus, loan amortization, and more. Choosing the perfect one really depends on what you need the app to do. If you’d rather write the problem out yourself by hand but have the app find the answer, there’s one for that. Or, perhaps you’re dealing with a really long and complex equation, and would rather the app write it for you; just download one that can take a picture of the question. Other use cases exist, too, as you’ll see throughout this list. Even better, Photomath shows you exactly how it got the answer, showing every single step necessary to solve the problem. This is perfect if you’re struggling with a math problem. After taking a picture of the problem, the app lets you edit it in case it didn’t read it correctly. From there, you can see every step necessary to solve it. A history of every equation you run through this app is stored for you to return to at any time. You can also favorite them to quickly find them again. Solutions can be shared with others so all they have to do is open a link to the Photomath website to see the problem and the answer. It’s free for iPhone, iPad, and Android. Download For: One of the major differences in this graphing calculator app versus some of the others you might find is that it doesn’t limit the number of expressions you can graph at once. It also supports function transformations via slider buttons, so instead of adjusting the expressions manually, you can just slide the bar left or right to quickly decrease or increase the value. If you tap an area of the graph, it will highlight the expression to show you exactly which one is responsible for that specific area of the graph, which is great for learning. Notes can be added next to any of the expressions to remind yourself of why you added something to the graph or to help you study. They don’t show up on the graph. Desmos can also store images on the graph, plot data points via tables, disable the grid lines, label the x and y-axis, and quickly undo and redo any changes made to the expressions. If you’re using it from a computer, you can share a graph through a special link, as well as download an image version. You can use this free calculator app from an Android, iPhone, or iPad, as well as directly from the Desmos website. Download For: There’s also a text box for entering an extra payment amount that you’ll pay per period, but it’s optional. After the payment amount per period is calculated, it shows you the total interest you’ll pay throughout the loan period and how much you’ll pay in total (interest plus principal). What makes this loan calculator different from some of the others in the App Store is that it has a full schedule to show you each payment it takes to pay off the loan, including how much of the payment will go to the principal balance and how much is reserved for paying off the interest. Another way to visualize how your loan will be paid off over time is through the Chart feature that gives a visual representation of the balance, interest, and total amount paid throughout the life of the loan. This calculator app is free to download for iPadOS and iOS 11 and newer devices, but you have to pay a few dollars to save multiple loans or to remove ads. It’s free to see answers, define terms, and plot points on a graph, but if you want step-by-step work and detailed explanations, you’ll have to subscribe to the Premium version. The app is chock-full of functions for several areas of math, so it’s great that each category has its own section, like one for basic math and another for linear algebra. It gets confusing if multiple areas are mixed into one big calculator, like how some calculator apps work. The app keeps a history of each section in the respective categories, so you can always return to Trigonometry, for example, to see those problems and answers even after you open a different area of the app. The only exception is that there isn’t a history of previous graphing problems. In fact, if you begin a graphing problem but don’t plot it, and then move to some other category, you’ll lose that progress. Mathway works on the web and is free for iPad, iPhone, and Android. Premium is as low as $3.33 /month if you pay $39.99 for the whole year. Download For: What makes this app stand out is that you can drag the Tip % option left and right to see, in real time, how it affects the total bill amount. After you enter the total amount of the bill, can see the tip amount and total price immediately. To refine what you’ll pay, adjust the tip percentage option and choose how many people the bill is for (you can pick 1–30). The rounding option will round the total bill amount up or down to the closest dollar amount, whichever direction you choose. This app is free with ads, but you can buy the Pro version to remove them. Download For: One great example where this calculator app is useful is when subtracting breaks from a work schedule, or when adding together multiple chunks of time to get the total time worked. As an example, you could do something like subtract 7:20 from 11:00 to figure up how much time you worked from 7:20 AM to 11:00 AM. Or, to see how many hours you worked all day, minus your lunch break, you could take 16:00 – 7:20 to see how much time passed between 7:20 AM and 4:00 PM (16:00). Subtract the 40-minute lunch you had (00:40) to get the total hour count (8 hours). Android, iPhone, and iPad users can download this app for free. There’s a full version you can get to remove the ads. Download For: Some supported operations include basic ones like plus, minus, divide, etc., as well as powers, roots, exponentials, brackets, trigonometry, inverse trigonometry, constants, and more. To erase or undo something, you can use the undo button or just scribble out the part that you want to be deleted. The app will recognize your scribbles as an eraser and instantly remove it from the equation. There’s a redo button, too. In the settings is an option to turn off automatic calculations so that you have more time to type before seeing the answer. Otherwise, if you have this option turned on, you’ll get answers midway through writing the problem. You can also adjust the number of decimal places shown in answers and choose to round or truncate approximations. This app is best used as a tablet or iPad calculator because the screen is so large. It’s difficult to use on smaller devices unless you stick with short problems. It’s $2.99 USD for Android, iPhone, and iPad. Download For:
