Tenwise is a number merge puzzle built on the column addition you learned at school. Slide the whole board, and numbers that meet add up. The catch: a sum may never go past the next round number. Make exactly 10 and it carries up to the tens, make exactly 100 and it carries up to the hundreds, and so on, for as long as you can keep the board clear.
Tenwise rules
- The board is 5 by 5 squares. A game starts with three numbers, each from 1 to 5.
- Each move slides every number on the board as far as it can go: up, down, left or right.
- When two numbers of the same kind meet, they join into their sum. Ones join with ones (1 to 9), tens with tens (10 to 90), hundreds with hundreds, and so on.
- A sum may never go past the next round number. 3 + 4 makes 7, but 7 + 5 would be 12, which is past 10, so those two stay apart.
- A sum that lands exactly on the round number carries up a place: 3 + 7 makes a ten, 40 + 60 makes a hundred, 300 + 700 makes a thousand.
- Numbers of different kinds never join, even when the sum would be round: 10 and 5 stay apart.
- A number joins at most once in each move. If three or more meet in a line, the pair nearest the side you slid toward joins first.
- After every move that changes the board, the number shown as Next is written into a random empty square. New numbers are 1 to 5 at first. After 400 moves, 6s, 7s, 8s and 9s start to turn up too, slowly more often as the game goes on, so the board gets harder and harder to keep clear.
- Every join scores its sum, so making a hundred scores 100 points. The game ends when no move can change the board.
How to play on this page
- Swipe on the board with a finger, drag with the mouse, or press the arrow keys. W, A, S and D work too, and so do the arrow buttons at the bottom of the game.
- Watch the Next box: it shows which number will appear after your move, so you can plan where it will be useful.
- The highlighter color inside each number shows how close it is to its round number. A 7 is mostly colored in, because it only needs a 3.
- Changed your mind? Undo takes back your last move. The same move afterwards brings the same new number, so Undo is a second look, not a second roll of the dice.
- Your game, your best score and your biggest number are saved in this browser, so you can close the page and carry on later.
Tips for a high score
- Learn the pairs that make ten: 1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5. You will see them everywhere.
- Be careful with big ones. A 6, 7, 8 or 9 can only join with a small number, so keep small numbers near them instead of piling up more big ones.
- Do not join small numbers too early. Two 3s make a 6, which is harder to use than two 3s that could each finish a 7.
- Keep your tens, hundreds and thousands together in one corner and slide mostly in two directions, so the big numbers stay out of the way of the small ones.
- Check the Next box before every move. A 5 coming up is perfect next to another 5, and a 1 can rescue a stuck 9.
- A full board is not the end if two neighbors can still join. Look for that one pair before you give up.
Frequently asked questions
- How is this different from other number merge games?
- In most merge games only equal numbers join, and each join doubles them. In Tenwise any two numbers of the same kind can join, as long as their sum does not go past the next round number. So the question on every move is not "where is the matching tile?" but "what does this number need to make ten?"
- Why is it called Tenwise?
- Because every number here grows in tens. Ten ones make a ten, ten tens make a hundred, and ten hundreds make a thousand, just like carrying the one in a written sum. Playing well means thinking in tens: what does this number need to reach the next round one?
- Why can’t my 7 and 5 join?
- Because 7 + 5 is 12, which goes past 10. A sum may reach the round number above it but never pass it. Your 7 needs a 3, or a 1 and a 2 that join first, and your 5 needs another 5.
- Why does a 10 not join with a 5?
- They are different kinds of number. Once ones add up to ten, the result is a ten, and from then on it only joins with other tens. That keeps each place separate, just like the columns in a written sum.
- How long does a game last? Is there a last number to reach?
- There is no last number, but every game does end. A relaxed game usually lasts 100 to 300 moves and makes numbers in the hundreds. Careful play can go on for well over a thousand moves and usually makes somewhere between 3000 and 8000, but after move 400 the bigger new numbers (6 to 9) slowly fill the board, so even the most careful game comes to an end. A 10000 is the stuff of legend.
- Can I undo a move?
- Yes, one move at a time. Undo puts the board, the score and the Next number back exactly as they were. Undoing the move that ended a game takes its result out of your best score again.
- Do I need an account or a download?
- No. The game runs in your browser on a phone, tablet or computer. Your game and your records are kept in this browser only, and clearing your browser data removes them.