In iPadOS 18, the whole iPad is a calculator app

The new Calculator app in iPadOS 18 is, at first glance, wildly unimpressive. When I installed the new operating system, which is now in public beta, I tapped the Calculator icon expecting something that felt uniquely tablet-focused and powerful. I got, well, the iPhone’s Calculator app — only slightly larger. It’s a nice addition to the iPad, sure, but there’s nothing here that took 14 years to make.

The Calculator app doesn’t really matter, though. I suspect you’ll hardly ever use it. What’s actually extremely cool and innovative about iPadOS 18 and iOS 18 is that there is a calculator baked into the operating system itself. Tap in the text box in Messages and type “225/4=” and it’ll automatically tell you that your friend owes you $56.25. You can type out your equation in the body of an email, then tap to replace it with just the final answer. So far, this works in basically any text box but only in Apple’s built-in apps; I suspect we’ll see it everywhere as apps update. It’s the kind of feature that immediately becomes second nature.  

But on the iPad, at least, it’s Math Notes that really shines. Instead of forcing you to work within the confines of calculator buttons, Math Notes lets you do your arithmetic however you like. You can create a Math Note from within the Calculator app, but the easier strategy is just to open up the Notes app and start drawing. Write “56 + 48 + 35 * 4 / 6 =” and, a second or two after you write the equals sign, the answer pops up (127.33, in case you’re wondering). Write a bunch of numbers in a column, draw a horizontal line underneath, and Notes will sum them up for you automatically. Change a number, and it’ll change the total.

You can do impressively wonky things within Math Notes, including solving equations and generating graphs. Its ability to work with variables is the most impressive thing I’ve seen: if you write out your equation and then change a variable, it’ll rewrite all your answers and redo all your graphs in real time. A lot of the more complex stuff is great for students and physicists and maybe not many others, but it’s extremely fun to play with. Oh, and fair warning: like any AI system, it will not be right all the time. YouTube is already full of fun examples of Math Notes getting things wrong.

Even in the best case, Math Notes is extremely exacting. It requires you to write neatly and carefully, for starters, which has been a challenge for my terrible handwriting. If the iPad doesn’t recognize a number or letter in an equation, it adds a dotted red border to the unknown bit and essentially asks you to try again. (I’ve had pretty good luck with number recognition, for what it’s worth, and a much worse experience with letters and other symbols.) You’ll also get the red border if the iPad can’t figure out the equation you’re trying to solve or if something is missing in your syntax. It doesn’t try to solve your problems or even tell you what they are — it’s like the Check Engine light in your car, just telling you something’s wrong.

In my testing so far, there are also lots of beta-type quirks left for Apple to work out. If you write an equation that takes up most of the screen, the solution will sometimes either appear on top of the equation or spill over the edge of the screen where you can’t see it anymore. Another feature in iPadOS tries to match your handwriting — and use AI to ever-so-slightly improve it as you write — but what it writes looks nothing like what I write. The app also gets tripped up easily by other things on your notes: I can write a list of numbers, and it works fine, but as soon as I write “food” next to one of those numbers and “beer” next to another, it gets confused.

There are a couple of obvious, simple things it can’t do. You can’t use one of the generated solutions in another equation — if you try to, say, divide that answer by six, it doesn’t recognize what you’re trying to do at all. The Math Notes answers aren’t actually part of your note, really. They’re more like a layer on top that you don’t get to touch or interact with. It’s weird.

My favorite use for Math Notes so far has been through the iPad’s Quick Notes feature. I grab the Pencil, swipe in from the bottom left corner of my iPad, and up pops a small note above whatever I’m doing. I write out whatever I’m trying to work out, get the answer, and I’m done. Now, I’m neither a student nor an engineer, the two demographics Apple seems to have most in mind, and as Math Notes improve, I suspect a lot of people will appreciate the ability to write notes that update and move in real time. For the rest of us, it’s the best way yet to figure out the rough cost of a weekend away or figure out who owes what once it’s all over.

I’m still not sure why it took Apple this long to put a calculator app on the iPad, but credit where credit’s due: the company found a uniquely touch- and tablet-friendly way to implement one. I just hope your handwriting is better than mine.