The rule is simple: If the current value is less than 0, meaning the current value is a negative number, the expression is True, and Excel applies the format (the red font). Figure E.

Meteorologists and negative numbers. By News-Times, The (Danbury, CT), News-Times Staff May 17, 2008.

You sometimes hear negative numbers on the weather forecast when it is absolutely FREEZING in winter, so Phil and Julie are here to tell us more in this edition of Maths Matters. These numbers are ...