Mini Sudoku 4×4
A Mini Sudoku is an ordinary Sudoku on a smaller board: four rows, four columns and four blocks of 2×2, filled with the digits 1 to 4. Nothing about the rules changes. What changes is that the whole puzzle fits in one glance, which is exactly what a child needs while the rule itself is still new.
The rule, in one sentence
Every row, every column and every 2×2 block must contain 1, 2, 3 and 4 - each exactly once. That is the entire game. On a 9×9 board the same sentence is true with the digits 1 to 9, so a child who has understood it here has understood full Sudoku too.
The first move on the board above
Look at the top row. It already holds 3, 2 and 1, and one square is empty. Four digits belong in every row, three of them are there, so the empty one can only be the 4. No technique, no pencil marks - just noticing what is missing.
That is the move the whole game is built on, and on a small board a child finds it without help. On a 9×9 grid the same reasoning is buried among eighty-one squares, which is why starting there so often ends in frustration.
Why this size for children
Sixteen squares is small enough to hold in your head. A child can look at the board and see all of it at once instead of losing their place halfway across a big grid, and a puzzle takes a minute or two rather than a quarter of an hour - short enough to finish while the interest lasts.
There is also nothing to get stuck on. We generated 200 of these boards and checked every one: all 200 could be finished by plain looking, without a single technique beyond spotting what is missing. That is also why this type has one level rather than five - on a board this small, "hard" would be a label with nothing behind it.
How to help without solving it for them
- Ask, do not point. "Which numbers are already in this row?" gets a child to the answer themselves; pointing at the square skips the part that teaches.
- One line at a time. Rows and columns are easier to see than blocks. Blocks come naturally once the first few squares are filled.
- Let the mistake happen. Putting the same digit twice in a row is the fastest way to learn why the rule exists - and on four squares it is easy to spot and fix.
When to move up
When a 4×4 stops being interesting - usually after a handful of boards - the next step is the 6×6, with blocks of 2×3 and the digits 1 to 6. It asks for a little searching without being a different game. After that, a full Easy 9×9 is the same rule again, on a board that finally has room to hide things.
Difficulties & scoring
This type has a single difficulty: the board is small enough that every puzzle is solvable by plain scanning, so extra levels would be names without a difference. The score multiplier for Mini Sudoku 4×4 is ×0.4. The "normal time" below is tuned for this type.
| Difficulty | Base score | Max (×0.4) | Normal time | Hints |
|---|---|---|---|---|
| easy | 150 | 120 | 1 min | 5 |
How the score is calculated
Your score builds up from 0 as you place correct numbers, up to the full base when the board is finished. Then two bonuses are added:
base × your progress × (1 + combo bonus + time bonus) × 0.4
- Progress: the live score climbs from 0 to the base as the grid fills with correct numbers.
- Combo bonus (up to +50%): keep a clean run for the full bonus. Each error or hint is a combo break that shrinks the bonus - but it never takes Sparks away below the base.
- Time bonus (up to +50%): beat the normal time and you earn extra, proportional to how much faster you were. Finishing slower than normal costs nothing - there is no time penalty.
- The total is multiplied by ×0.4 and never drops below 0.
Coins
The coins you earn reflect your score - the more Sparks, the more coins (about 1 coin for every 45 Sparks, minimum 1). Spend coins in the Shop on hints and Jokers.
Tip: a clean, hint-free solve under the normal time scores the highest. The Daily Challenge is always Classic and fully scored.