Step up to the carnival booth. A math fact hangs on the sign, four plates stand on the shelf, and only one of them has the right answer. Pull back the slingshot, aim, and let go. Smash the right plate and it is 10 points and a new fact. Hit a wrong one and it shatters, your streak is gone, and the fact stays up until you find the answer.
The wrong plates are not random numbers. For 7 × 8 they are the answers children really give, like 54, 63 and 48, so a half-remembered fact is not enough to pick the right one at a glance. Only your first shot scores, so shooting every plate in turn gets you nowhere, and the clock keeps running.
Choose the easy booth, where the plates stand still, or the hard booth, where they ride a conveyor belt and you have to aim ahead of the one you want. Rounds last 60 seconds. The leaderboard beside the booth keeps the ten best scores for each booth, with the names you type, saved in your own browser and nowhere else.
Press anywhere on the booth and drag back, down and away from where you want the rock to go, then let go. A dotted line shows where it will land. Pull to the left and the rock flies to the right, just like a real slingshot. On a keyboard, the arrow keys aim and Space shoots.
In the easy booth the four plates stand still on the shelf. In the hard booth they ride a conveyor belt from left to right, so you have to shoot where the plate will be when the rock gets there, not where it is now. Each booth has its own leaderboard.
Breaking the right plate with your first shot is worth 10 points. Get three in a row and every hit after that is worth 20 until you break a wrong plate. Breaking the right plate after a wrong one earns nothing, but it does bring up the next fact.
Only in this browser on this device. The names and scores are never sent anywhere, so a different computer or browser has its own board. Clear leaderboard removes every score and name, and so does clearing this site's data in your browser settings. A first name or nickname is all a board needs.
Multiplication is selected to start with. Tap the buttons above the booths to switch to addition, subtraction or division, or to mix them. Both numbers run from 1 to 9 by default, and “Change what to practise” widens or narrows the range.