In the previous lesson
you learned that some word problems have too much information. The
information needed to solve a problem is called relevantinformation. 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?
