Reading scales with unmarked divisions

Some thermometers have scales with both marked and unmarked divisions. You must first make sure what each small division represents.

Thermometer A is marked in tens. The unmarked division between each pair of marked ones is the halfway value (-5, 5, 15...), so the reading is closest to the 15ºC division.

Thermometer B is marked in fives, with four unmarked divisions between each pair. That means the unmarked divisions are each 1 degree apart. The reading is 2 degrees below the 0ºC mark, so the temperature is -2 ºC