What is the new temperature in Chicago, if one morning it was #-8^\circ F# and over the next six hours the temperature rose 25 degrees Fahrenheit?

1 Answer
Oct 26, 2014

Since the temperature rose #"25"^o"F"#, that means the temperature increased by #"25"^o"F"#. So you should add #"25"^o"F"# to the original temperature of #"-8"^o"F"#.

#"Final temperature"# = #"-8"^o"F"# + #"25"^o"F"# = #"17"^o"F"#

If you don't have a calculator available and you don't want to make a number line, you can reverse the order of the addends, like this:

#"Final temperature"# = #"25"^o"F"# + (#"-8"^o"F"#) = #"17"^o"F"#