Fill thermometers to match the row and column clues
How to Play
Tap an empty cell to fill it with mercury
Tap a filled cell again to mark it as empty (X)
Tap an X cell again to clear it back to empty
Rule 1: Fill from the Bulb Continuously
Thermometers must be filled starting from the bulb (rounded end) with no gaps in between.
Rule 2: Match Row/Column Clue Numbers
The number beside each row/column is the total filled cells required in that line.
Completed Example
Fill each thermometer starting from the bulb (rounded end)
You cannot skip cells — fill consecutively from the bulb
A thermometer can be left completely empty
The number beside each row/column is the total filled cells in that line
Tip
Mark all cells with X in rows or columns where the clue is 0
If the clue equals the number of thermometer cells in that line, fill them all
Work backwards from the tip (opposite end of bulb) to quickly determine empty cells
Thermometer puzzles strengthen constraint satisfaction problem (CSP) solving skills. Processing row/column sum constraints and sequential ordering simultaneously activates working memory and logical reasoning.
Pillai, J. A., et al. (2011). Association of crossword puzzle participation with memory decline. Journal of the International Neuropsychological Society, 17(6), 1006-1013.
Brooker, H., et al. (2019). The relationship between the frequency of number-puzzle use and baseline cognitive function. International Journal of Geriatric Psychiatry, 34(7), 932-940.