Find One-Third of 45. Add 15. Divide by 6. Multiply by 25.
Those who worry that the increasing use of calculators and microcomputers is undermining the mathematical abilities of today's students might have been reassured had they observed the first Lane County Mental Math Competition in Eugene, Ore., this month.
Eighty 3rd- through 8th-grade students representing 15 school districts demonstrated that the human mind is still a remarkable calculating tool.
Students were asked a series of 20 questions that required them to perform complex computations in their heads--without the benefit of calculators or even pencil and paper. Questions were read at a pace slightly slower than ordinary conversation and could not be repeated. Students then had to jot down their answers as quickly as possible.
Seventh graders, for example, were asked for rapid determinations of whether the number 810 is divisible by 5 and 3 and whether one-half divided by one-third is more than one.
They were also asked to:
Find one-third of 45. Add 15. Divide by 6. Multiply by 25.
Take seven-tenths. Add five one-hundredths. Subtract twenty-five one-hundredths. Multiply by 2.
Find 10 percent of 200. Multiply by 60. Subtract 199.
Among the mathematical challenges presented to 4th graders were the following:
Start with the number of meters in 200 centimeters. Multiply by 10. Add 75. Subtract 15.
Start with the number of min-utes in four hours. Subtract 200. Now multiply by 100. Subtract 10.
The competition was sponsored by the Lane Education Service District, one of 27 consortia established throughout the state to encourage cooperation between school districts.
According to Jeff Foreman, information assistant for the Lane County consortium, the winners in each grade generally answered about 17 or 18 of the 20 questions correctly. He said that two students--7th grader Kristen Albrethsen from Junction City and 6th grader Brian Brown from Cottage Grove--solved all 20 problems.
Countywide contestants were chosen in competitions at the classroom, school, and district levels--the same process the county uses for its annual spelling bee. Districts had asked the consortium to sponsor a mathematics competition because of the spelling bee's success.
"It's a good opportunity to allow kids to show off how much they know," said Mr. Foreman. "It also shows that we in the education business are doing our jobs."