Leaderboards
Escape the grid with the snake on and post your time under a nickname. There is a board for each grid size and snake speed, and each keeps the 100 fastest escapes 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 escapes on 10 × 10 subtraction, Normal snake. Resets at midnight, US Eastern time.
No escapes on this board today yet. Fill the grid and post the first time.
How to Play
Choose a grid — 10 × 10 for minuends 10 through 19, or 12 × 12 for minuends 12 through 23 — pick a snake speed, and press Play or the Enter key. The first cell on the path lights up; subtract the column number from the row number and type the difference. A one-digit difference is judged the moment that digit lands; a two-digit one waits for both. A correct answer turns the cell green and moves the marker on; a wrong one shakes, clears, and waits for a retry — nothing is ever skipped.
Here is exactly what to type. Each key below is one press.
One digit. Press 3 and the cell clears at once.
Two digits. Press 1 and then 8; the answer is judged on the 8.
The correct difference is 9, not 8, so the cell shakes and clears. Retype the same fact; it is never skipped.
- Backspace fixes a digit
A digit typed by mistake before the last one can be removed with Backspace or the keypad's delete key; the cell is judged only once the last digit lands.
- The clock only counts up
There is no time limit on a round. The clock on screen just tracks how long the grid has taken, and an escape records that time as your best for the grid size.
- Headers in order for a first look
The switch on the card keeps the minuends and the numbers to take away running in order along both edges, so a learner meeting the grid for the first time can find each fact where it is expected.
Why the Grid Never Goes Negative
Down the left edge sit the minuends: on the 10 × 10 grid, 10 through 19; on 12 × 12, 12 through 23. Across the top sit the numbers you take away: 1 through 10, or 1 through 12. However the headers shuffle each round — both axes independently — every row's smallest possible minuend is 10 (or 12), exactly the largest number the columns ever ask you to subtract, so no cell can ever land below zero. Answers across the board run from 0 up to 18 on the 10 × 10 grid, or up to 22 on 12 × 12.
The Frosted Cells
One column value in every row lands on exactly the grid's own size: a difference of 10 on the 10 × 10 grid, or 12 on the 12 × 12. Those cells are frosted from the start of the round, and clearing one freezes the snake for two seconds, the same reward the multiplication grid gives its squares. Because every minuend above the smallest has exactly one number to subtract that produces this difference, a 10 × 10 grid carries nine frosted cells and a 12 × 12 grid carries eleven — one fewer than the grid has rows, since the smallest minuend cannot reach a difference that large.
The Snake
The snake sets off once the first row is filled and at least eight seconds have passed, then follows the same serpentine path you are filling: row one left to right, row two right to left, and so on. At Normal speed it steps once every 2.4 seconds on the 10 × 10 grid or 2.8 seconds on 12 × 12, picking up about 3% more speed with every row it enters. A wrong answer lets it lunge a cell closer; turning a corner buys two cells of room; a frosted cell freezes it for two seconds. Fill the last cell first and you have escaped; let it reach your cell and the round ends there.
Keyboard, Keypad, and Sound
Type with the number row or the numeric keypad on a computer, and each key press lights the matching key on the on-screen keypad so someone watching can follow along. On a phone or tablet, tap the keypad directly; it is the same one Math Builders uses for practice, so a returning learner needs no introduction, and the grid never has to compete with the device's own keyboard for space.
A soft chime marks a correct cell, a longer tone marks a frozen snake, and a low note marks a miss; the speaker icon on the card silences all of it and remembers the choice on that device.
Using the Subtraction Speed Grid in Class or at Home
On a projector, the shuffled headers make a fair whole-class round: nobody can win by memorizing where a fact sits. Headers in order with the snake off suits a first or second grader meeting the grid for the first time; shuffled headers with the snake on Normal is where most classes that already know the take-away facts will spend their time.
The grid rewards a fact that is already fast; it does not build one that is missing. Pair it with printable subtraction worksheets and read addition and subtraction fluency for how the underlying practice should be paced.
For the bubble-based version of the same facts, try Subtraction Bubble Tank, or see how the multiplication Speed Grid handles a wider, always-positive table. Every subtraction game lives on the subtraction games hub, and every operation's games are on free math games.
Frequently Asked Questions
Fill every cell before the snake reaches the one you are on. The path snakes through the rows, so you fill the first row left to right, the second right to left, and so on. Fill the last cell first and you have escaped.
Minuends run down the side — 10 through 19 on the 10 × 10 grid, or 12 through 23 on the 12 × 12 — and the numbers to take away run across the top. The smallest minuend equals the largest number you subtract, so no cell is ever negative.
The cell shakes and clears, and you type the answer again; a cell is never skipped. If the snake has already set off, a wrong answer lets it lunge one cell closer.
The cells where the difference equals the grid’s own size: 10 on the 10 × 10 grid, or 12 on the 12 × 12. Clearing one freezes the snake for two seconds. There are nine of them on the smaller grid and eleven on the larger.
Yes. Turn on Practice before pressing Play and the grid, the path, and the timer stay while the snake stays out entirely. Practice rounds are never posted to a leaderboard.
Escape with the snake on and post your time under a nickname, with an optional state or country. Each grid size and speed keeps its own top 100 fastest escapes for the day, week, month, and year. Times under 40 seconds (10 × 10) or 60 seconds (12 × 12) are refused.