How to play Thermometers puzzles.

Your first grid

Six thermometers on a 4x4 grid. Row numbers run down the left, column numbers along the top, and both count from the top-left corner. Solve it before you read the steps.

Tap a cell and mercury rises from the bulb to it. Tap the top of the mercury to let it fall back. Row numbers 3, 3, 0, 2. Column numbers 2, 3, 1, 2.

The solve, move by move

1. Row 3 has a 0, so all four of its cells are empty.
2. Column 2 needs 3 filled cells. Its row 3 cell is empty, which leaves exactly three cells (rows 1, 2 and 4), so all three fill.
3. Row 1, column 2 is filled, and it sits in the top thermometer. Mercury can't skip a cell, so the bulb to its left fills too.
4. An empty cell cuts off everything beyond it. The left thermometer starts in row 2 and is empty in row 3, so its row 4 cell is empty. The right thermometer is empty in row 3, so its row 4 cell is empty as well.
5. Row 4 needs 2. Column 2 is already filled and columns 1 and 4 are empty, so column 3 fills.
6. Column 1 needs 2, and rows 3 and 4 are empty, so rows 1 and 2 fill.
7. Column 3 needs 1, and row 4 already has it, so rows 1 and 2 of column 3 are empty.
8. Column 4 needs 2, and rows 3 and 4 are empty, so rows 1 and 2 fill. Rows 1 and 2 now have 3 each, which matches their numbers. Solved.