Number Stacks

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Sort scrambled digits into stacks of one number each.

on puzzlelab.dev

Number Stacks' daily board for 19 October 2026 at desktop size: ten stacks of four mixed digits and two empty stacks, with Complete 0/10 and Moves 0 above and Undo below

Number Stacks is a daily sorting puzzle from PuzzleLab. The board has rows of stacks filled with mixed digits and two empty stacks, and you move the top digits around until every stack contains only one digit. It works like the ball-sort puzzles found in mobile apps, with numbers instead of colours.

About Number Stacks

Number Stacks deals a board of twelve stacks, each holding up to four digits, with two left empty. The digits 0 to 9 are mixed among them, and the goal is to sort the board so that every stack contains only one digit, repeated.

You tap a stack to select it and tap another to move its top digit there. A digit can only go onto a matching digit or into an empty stack, and if several matching digits sit together at the top, they move as a group. A counter shows how many stacks are complete and how many moves you have made, and Undo takes back mistakes.

The daily board is generated from a seed based on the date in Pacific time, so everyone gets the same one, and it changes at midnight there. A practice mode deals new boards whenever you like. A stats panel records your daily results in the browser, a share button sums up your solve, and nothing needs a sign-up. PuzzleLab's other dailies include Summit, Word Safe, Word Weave and Clear the Deck.

It suits players who enjoy calm sorting puzzles and planning a few moves ahead.

How to play Number Stacks

Open Number Stacks on PuzzleLab and start the daily puzzle.
Tap a stack to select its top digit, then tap a destination stack.
Move only onto the same digit or into an empty stack; matching digits on top move together.
Use the empty stacks as temporary space and Undo if you get stuck.
Finish when every stack contains a single digit, then share your move count.

Screenshots

The same Number Stacks daily board at phone size: two rows of six stacks fill the narrow screen, with the move counter above and Undo below

Tips

Keep at least one stack empty for as long as you can.
Look for digits buried under only one other digit: they are the easiest to free.
Build one complete stack early to reduce clutter.
Plan two or three moves ahead before filling an empty stack.