Stumped by a revolving door
It was a question about a revolving door that stumped our group of Kiwi 15- year- olds.
Our five Year 11 students at Waiuku College who had agreed to try out sample questions from the Pisa tests sailed through the online science questions, which tested their understanding of evolution and their ability to apply a given formula to a computer- simulated case study.
Most also got the right answers to questions testing simple arithmetic. Then they hit the revolving door. “A revolving door includes three wings which rotate within a circularshaped space,” the question said.
“The inside diameter of this space is 2m ( 200cm). The three door wings divide the space into three equal sectors.”
The first part of the question was: “What is the size in degrees of the angle formed by two door wings?”
The answer required knowing that there were 360 degrees in a circle, and dividing by 3. Only one student got it right.
The second part said: “The two door openings [ inside and outside] are the same size. If these openings are too wide the revolving wings cannot provide a sealed space and air could then flow freely between the entrance and the exit, causing unwanted heat loss or gain. What is the maximum arc length in centimetres that each door opening can have, so that air never flows freely between the entrance and the exit?”
To get the right answer, students had to know the formula for the circumference of a circle ( 2π x r), where is a long number starting with the digits 3.14 and “r” is the radius of the circle ( 100cm in this case). Only one student got that far.
Then they had to divide by 6 because the maximum size of each door opening was one- sixth of the circumference. Even the one student who knew the formula stumbled at this point.
“We forgot the actual formula,” said Mikayla Capes, who had done well until then.
The consensus, as Mauriora Kaihau put it, was: “The science was easier than the maths.”
Maths was the weakest Pisa subject for Kiwi 15- year- olds generally, and the revolving door question suggests that what we lack is not the thinking ability but the basic rote- learned knowledge — in this case, the formula.
The students had their own views on why Kiwi scores were declining.
“Maybe they are not taught how they need to be taught,” said Latesha Latu.
“Sometimes I feel it can be tough on both ends [ of a class] — the inbetweens are getting what they need, but the high end and the low end are not being catered for enough.”
Waiuku deputy principal Gowan Ditchburn, who supervised our test, said every school faced the dilemma of coping with students of differing abilities.
At Waiuku they start streaming top students into an extension class in Year 10. Those who were not picked for it, like Nic Ruygrok, said it “kind of made us feel inferior”.
Zach Whitley, who was also left out, said: “Say you’re talking to your friends [ in the extension class] and they have an assignment due, and sometimes they are worth credits. I could do them with my eyes closed, but [ pupils in regular classes] don’t really get the opportunity.”
Ditchburn said streaming also reduced the chances for slower students to learn from the faster ones — a practice that helps the faster students understand what they are learning, as well as pulling up the slower ones.
“Equally, there are other arguments about teachers teaching to the middle and therefore not meeting the needs of the students at the extremes [ in non- streamed classes],” he said.
“Personally I can see arguments for and against on both sides of the debate.”
It suggests that what we lack is not the thinking ability but the basic rote- learned knowledge.