Leaderboards
When a real round overflows, post your bubble count under a nickname. There is a board for each fact set, and each keeps the 100 highest counts of the day, the week, the month, and the year. A nickname is all you need; a state or country is optional, and the game never asks for a real name, a town, or an email address. Practice rounds stay on your device.
Top 100 rounds on the 2 to 9 facts, most bubbles popped first. Resets at midnight, US Eastern time.
No rounds on this board today yet. Pop some bubbles and post the first score.
How to Play
Choose the facts, 2 to 9 for the core table or 1 to 12 for the full one, and press Play or the Enter key. Seven bubbles float up, each showing a fact, and the water starts to rise. Type the product of any bubble you know. The bubble pops the moment the last digit lands and the water drops a step; a new bubble floats up to take its place. There is no Enter key between answers and no bubble you must answer first. Pop the ones you know cold, and the hard ones can wait for a calmer moment.
Here is exactly what to type. Each key below is one press.
Two digits. Press 1 and then 2; the bubble pops on the 2.
One digit. Press 6 and the bubble pops at once, as long as no other bubble's product starts with 6.
Three digits, only with the 1 to 12 facts. The game waits for all three before it judges.
If no bubble in the tank starts with 5, the game says so on the 5 and the water rises a little. Check the bubbles before you type.
- Drain the tank to clear a stage
Pop faster than the water rises and the level drops to the floor. The plug opens, the tank empties, the stage is cleared, and it refills a little higher with a faster pump. Three quick pops in a row will do it on stage one.
- Three in a row drains the tank
Pop three bubbles without a miss and the water drops an extra step with a swirl. A wrong answer adds a splash of water and starts the count again.
- The golden bubble
Once you have popped a few, a golden bubble appears now and then. Pop it and every bubble in the tank goes with it.
- The water speeds up
An untouched tank overflows in about half a minute, and the pump gets faster the longer you last and with every stage, so every round ends. The score is what you popped before it did, and how many stages you cleared.
Why You Choose the Bubble
Most fact games hand you one question at a time. Bubble Tank hands you six and lets you pick. That changes what the game practises: a learner who knows the 2s and 5s cold can pop those first and buy time to work out 7 × 8, which is exactly how fluent people handle arithmetic. The known facts are quick, the shaky ones get thought about, and nobody is stuck on a single question while a clock runs out. Because the game only judges an answer once it could not be any bubble in the tank, a wrong answer is always a real miss, never a mistyped first digit.
The rising water is the pressure, and it is honest pressure: you can see it, it moves at a steady pace, and every pop pushes it back by the same amount. Learners work out quickly that popping the easy bubbles fast is worth more than staring at a hard one, and that is the habit the game is there to build.
Keyboard, Keypad, and Sound
On a computer, type with the number row or the numeric keypad. Each physical key press also lights the matching key on the on-screen keypad, so a child watching can follow along. On a phone or tablet, tap the on-screen keypad. It is the same keypad Math Builders uses during practice, so a learner who already uses the app needs no explanation. The game never opens the phone's own keyboard, so the tank stays visible while you type.
The sounds are short and watery: a bright blip for a pop, a rising run for a golden bubble, a gurgle for the drain, a low tone for a miss, a tick when the water nears the line, and a low double note for the overflow. The speaker button on the card turns all of them off, and the choice is remembered on that device. Nothing plays until you press Play, so the page is silent on load.
Using Bubble Tank in Class or at Home
On a projector, the tank is easy to read from the back of the room, and the choice of bubble makes it a good call-out game: one student has the keyboard, the class shouts the products they see. Practice mode with the 2 to 9 facts is a calm way to introduce it; the full 1 to 12 set with the water on is where a class that already knows the table goes for a high score. A best count on the board is a stronger motivator than any grade.
Bubble Tank is a game, not a diagnostic. It rewards knowing which facts are easy for you; it does not tell you which are slow on a normal day. For that, run the multiplication timed test, which records every fact's response time, or use multiplication facts practice with its slow-fact feedback. A learner who keeps leaving the same bubbles until the tank overflows benefits from a week on the times tables practice hub before coming back. The game works alongside that practice; it is not a replacement for it.
For a different kind of round, the Sixty Second Sweep asks for the factors of each product under one clock, and the Speed Grid fills a whole table with a snake on your heels. See all free multiplication games on Math Builders.
Frequently Asked Questions
Drain the tank. Pop bubbles faster than the water rises and the level drops all the way to the floor; the plug opens, the tank empties, and the stage is cleared. It refills a little higher with a faster pump and the next stage begins. Every round ends with an overflow eventually; your score is the bubbles you popped and the stages you cleared. Beat your best, then beat the leaderboard.
Whichever one shows the product you typed. No two bubbles in the tank ever share the start of a number, so the game always knows which bubble you mean, and it pops the moment the last digit lands.
The water rises a little and your three-in-a-row count starts over. Backspace removes a digit before the answer is judged; the answer is only judged once it could not be any bubble in the tank.
A rare bubble that shows up once you have popped a few. Pop it and every bubble in the tank goes with it, and each one counts toward your score.
The tank is closed with a glass lid, and the rubber duck floats on the surface. As the water rises the duck rises with it toward the lid, and the edges of the tank glow red. If the water reaches the lid, the duck goes under and sinks to the bottom upside down, and the round is over. Keep the duck away from the lid.
Yes. Turn on Practice before you press Play. The water rises at a quarter of the pace and never reaches the line, and you end the round with the flag button whenever you like. Practice rounds are never posted to a leaderboard.
After a real round overflows, post your bubble count under a nickname and, if you like, your state or country. There is a board for each fact set, keeping the 100 highest counts of the day, the week, the month, and the year in US Eastern time. Nicknames go through a word filter, and the game never asks for a real name, a town, or contact details.