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Problems and Problem Solving - Ministry of Education

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should go about gathering the needed information – either through making assumptions <strong>and</strong>/or<br />

estimates, carrying out research or by performing calculations.<br />

Open problems usually produce different results, since each student may make different assumptions<br />

<strong>and</strong> estimates or may choose different facts <strong>and</strong> figures to include in the task. It is important,<br />

however, that students are able <strong>and</strong> allowed to justify their assumptions, estimates <strong>and</strong><br />

choices in light <strong>of</strong> the answers that they received.<br />

Open problems are usually derived from two main sources by:<br />

i. transforming routine tasks into non-routine problems; <strong>and</strong><br />

ii. using real-world situations.<br />

Transforming routine tasks<br />

Enrico Fermi, a mathematician, developed <strong>and</strong> successfully used open problems with his students.<br />

These problems demonstrate how routine tasks can be transformed into open non-routine<br />

problems. The table below shows some routine problems in the first column <strong>and</strong> then some <strong>of</strong><br />

Fermi’s open variations on these in the second column.<br />

Routine problems<br />

Open problems<br />

(adopted from Peter-Koop, 2005)<br />

The polar bear problem<br />

The average child in a school weighs 35 kg; the<br />

polar bear at the zoo weighs 665 kg. How many children<br />

will it take to weigh as much as the polar bear?<br />

How many children are, together, as heavy<br />

as a polar bear?<br />

The water problem<br />

Each day you use 13 litres <strong>of</strong> water. How many litres<br />

<strong>of</strong> water do you use in a week?<br />

How much water do you use in 1 week?<br />

The traffic problem<br />

How many cars <strong>of</strong> length 20 m are in a traffic jam<br />

that stretches for 3 km, if a space <strong>of</strong> 6 m is between<br />

each car?<br />

There is a 3 km traffic pile up on the highway.<br />

How many vehicles are caught in this<br />

traffic jam?<br />

Fermi’s wording forces students to make many assumptions or estimates if they are to attempt<br />

to solve the problems. For example, with the traffic problem, students must seek answers to the<br />

14 PROBLEMS AND PROBLEM SOLVING<br />

<strong>Problem</strong><strong>Solving</strong>.indd 14<br />

8/24/12 6:55:34 PM

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