In
the previous lesson you learned that some word problems have too much
information. The information needed to solve a problem is called
relevant
information. The information that is
not needed is called
irrelevant information.
relevant
irrelevant
important information
not
important information
need this to solve
problem
not needed to
solve problem
In the following word problems, identify the
relevant information or the irrelevant information.
Joey is 8 years old, and his
sister is 5 years older. His mother is 45. How old
is his sister?
What is the irrelevant
information?
Buffalo got 78 inches of snow
this winter. Syracuse got 120 inches of snow. Albany got
52 inches of snow. Syracuse got how much more snow than
Buffalo?
What is the irrelevant
information?
A bread recipe calls for 3 cups
of rye flour, 2 cups of wheat flour, and 1
cup of water. How many cups of flour are needed in all?
What is the irrelevant
information?
OK, ready to try some more
difficult problems? Click on the picture to
check your answer!
Janet wants to put a fence
around her yard. She needs to find the perimeter of her
yard. The four sides measure 55 feet, 68 feet, 90
feet, and 45 feet. There is a tree that measure 75 feet
tall in the middle of the yard. How many feet of fencing
does she need to buy?
OK, in order to solve this
problem, what numbers are needed?
John is a marathon runner.
His best time is 2 hours 15 minutes. To possibly win the
Boston Marathon, he must run it in 2 hours 7 minutes.
Yesterday he ran 20 miles. How much time must he shave off
his time to possibly win the Boston Marathon?
OK, in order to solve this
problem, what numbers are needed?
