The alarm that makes you do math

A math alarm works for a reason that has nothing to do with being clever: arithmetic is the one thing a sleeping brain cannot fake. You can swipe in your sleep. You can tap a button in your sleep; people dismiss ordinary alarms with no memory of doing it every single morning. Nobody computes 64 + 37 in their sleep, and an alarm that only stops for the exact answer turns that limitation into a lock.

In Risly, math is one of seven missions that can silence the alarm (chained arithmetic, a memory game, scanning an object, a QR code, a barcode, shaking the phone, or camera-counted push-ups), and the full list lives on the missions page. This page is about one of them: what the math mission actually does, what the problems do to a half-awake brain, and when you should pick a different one.

What is a math alarm and how does it work?

The detail that separates a working math alarm from a gimmick is chaining. One problem is a speed bump: a half-asleep person can fluke a single answer. Risly hands you a run of one to ten problems (three by default), with a progress bar that fills as you clear them. Get one wrong and the screen shakes, the digits flash red and the field clears: you keep the problems you have already solved, but you go nowhere until the current one is right. There is no route through the run that skips computing every answer, and by the time you have computed three in a row you are demonstrably awake, because you could not have done it otherwise.

There is a second design constraint that is easy to miss: every difficulty stays solvable in your head. That is deliberate. The mission is an anti-snooze gate, not an exam. A problem you cannot do mentally at 6:40am does not wake you up, it traps you next to a ringing phone, and a trapped person deletes the app. So Risly’s hard tier tops out at two-digit-times-one-digit multiplication and exact division, not long division with remainders. Difficult enough to demand real attention; never so difficult that the alarm becomes unwinnable.

What does mental arithmetic do to a brain that just woke up?

It runs straight into the wall the brain wakes up behind. The first minutes of every morning happen under sleep inertia, the groggy transitional state in which attention, decision-making and working memory are all measurably impaired. Lynn Trotti’s review in Sleep Medicine Reviews (2017) is the standing account of how far those faculties drop in the first minutes; Hilditch and McHill, pooling the same literature in Nature and Science of Sleep (2019), put the window at 15 to 60 minutes for most people, worst when the alarm pulls you out of deep sleep, which is exactly what an early alarm tends to do.

How bad are those first minutes? The cleanest number comes from a small controlled study by Adam Wertz and colleagues in JAMA (2006): in the minutes immediately after waking, cognitive performance was worse than after 26 hours without sleep. And here is the detail that makes it this page’s favourite piece of research: the task they used to measure that impairment was two-digit addition. Sleep scientists hand people arithmetic on waking precisely because it is the kind of thinking sleep inertia breaks. A math alarm takes the measurement instrument and turns it into a lock.

Now the honest part, because it is also the reason to trust the rest of this page: no published study has tested whether math alarms wake people better than ordinary alarms. Not one. The mechanism is plausible (forcing working memory to engage during the window when it is offline, keeping you upright and thinking through the minute in which most people roll back under), and arithmetic sits in the standard cognitive batteries sleep researchers run on freshly woken subjects, including the snooze study by Tina Sundelin’s team in the Journal of Sleep Research (2024). But plausible is not measured, and we would rather tell you that than dress a mechanism up as a finding. What the mission verifiably does is narrower: it makes dismissing the alarm impossible to perform asleep.

It also has a limit worth knowing before you buy anyone’s marketing, ours included. Solving five problems does not end sleep inertia. Megan Jewett’s time-course study in the Journal of Sleep Research (1999) tracked the fog dissipating over two to four hours, with the steepest recovery in the first half hour. The mission’s job is to carry you through the worst opening minutes without letting you fall back asleep; the rest of the curve belongs to light, movement and time.

One more effect that nobody designs for and everybody reports. We will label it for what it is, an observation rather than a measurement: being handed 64 + 37 by a phone at full volume is genuinely infuriating, and irritation is a stimulant. Nobody drifts back to sleep mid-grudge.

Can you just use a calculator?

You can, and it is worth being precise about what that involves, because "I’ll cheat with the calculator" is the first objection everyone raises. While the alarm rings, the mission occupies the screen. Reaching a calculator means walking away from a ringing phone or grabbing a second device, typing in both operands, reading the result and typing it back, for problems that were deliberately designed to be solvable in your head faster than that. The detour costs more effort than the solve. Which is the quiet joke of the whole objection: anyone coordinated enough to operate a calculator is awake. The mission does not care how you got there.

How hard should you set the math problems?

Harder than feels fair at 11pm, because the person choosing the difficulty is not the person who will face it. Almost every mission alarm decays the same way: for the first days it is a revelation, then you adapt: not consciously, you simply get better at doing the thing while barely awake, the same way you learned to sleep through your old tone. Three rules keep the math working past week three.

1. Start at medium, chained three times. That is Risly’s default for a reason: two-digit sums you have to actually think about, three in a row. Easy single problems become dismissible on autopilot within a week.
2. Put the phone across the room anyway. Math plus distance beats math. The mission stops the autopilot dismissal; the distance stops you completing the run face-down in the pillow and rolling straight back over.
3. Escalate the morning it stops hurting. The day you clear the run and feel nothing, raise the difficulty, lengthen the chain (the editor goes up to ten problems), or switch mission entirely. Novelty is carrying more of the load than arithmetic is, and pretending otherwise is how month-two uninstalls happen.

Alarmy has a well-regarded math mission too; its difficulty scale climbs further than ours, and it runs on Android, which Risly does not. The difference is what sits behind the mission: in Alarmy a snooze remains available by default; in Risly there is no snooze button anywhere in the app. If the mission is the lock, a snooze button is a key taped under the mat. The full comparison, cons of our own app included, is at Alarmy alternatives.

When is math the wrong mission?

More often than a page named after the math mission should probably admit. We would rather you pick the mission that matches your failure mode than pick ours out of loyalty.

• If you dismiss alarms with no memory of it, arithmetic alone may not save you, because you are still in bed when you solve it, and bed is where the relapse happens. Use the camera scan on an object in another room instead; the case for making distance itself the mission is the whole argument of the alarm that gets you out of bed.
• If you have dyscalculia, or numbers spike your anxiety, do not hand yourself a math test at 6am. The shake and scan missions gate the alarm just as firmly, with none of the dread.
• If you have learned to solve the run in a fog (and after months, some people genuinely do), treat it as a signal, not a victory: escalate, lengthen the chain, or rotate to another mission for a month.

And the category-wide caveat, stated plainly: Christopher Hilditch and Andrew McHill’s review in Nature and Science of Sleep (2019) went looking for evidence behind every sleep-inertia countermeasure people swear by (caffeine and light included) and found the base thin across the board. Missions are no exception. What survives that honesty is still worth having: an alarm you must solve takes longer to silence, and it cannot be silenced by accident.

Does a math mission fix a short night?

No, and any app that implies otherwise is selling you something. Arithmetic at 6:40am can get you vertical after five hours of sleep; it cannot make five hours function like eight, and the grogginess you are fighting scales with the debt behind it. If every single morning is a war, the mission is treating the symptom.

A made-up but typical example, not a study. Leah, 24, a nursing student on rotating placements, ran an easy single problem for two months and eventually caught herself having solved it with no memory of that morning at all. She switched to medium, chained three, phone on the dresser. The first week she hated everyone. By the third she noticed the difference was not the math itself: it was that she had never once made it back into bed after standing up to solve it. The chain got her brain on; the two metres got her out.

The part that has to work before the math matters

A math mission is worth nothing if the alarm never rings. And that, not puzzle design, is where most alarm apps actually fail: muted by a Focus, killed in the background, undone by the silent switch. Risly schedules its alarms through AlarmKit, Apple’s iOS 26 alarm framework, so they fire like the built-in Clock app’s: through silent mode, through Do Not Disturb, even after a force-quit. That guarantee is the floor the mission stands on, and the full reasoning lives on the anti-snooze page.

Alarm that makes you do math: common questions