Types of reasoning

Distribution (Percentage)

Explanation and Representative Examples from students’ questionnaires

Area calculations based on plane geometry proof

15.8% (N = 9)

Explanation The students related to definitions, axioms, and proof in plane geometry and wrote the solution as a geometrical proof.

A link was made between the problem and plane geometry.

Examples

“…we will mark the sides of the large square as X… [1A]

we will place AB parallel to HN…” [24A]

“…we will prove that MDNC is a rectangle” [26A]

“…EF is parallel to AB…” [51A]

*a fine example can be found in questionnaire [24A]

Area calculation

40.4% (N = 23)

Explanation The students related to the geometrical figures as given figures, such as: rectangles or trapezoids as givens. They used known formulas to calculate areas.

“… we will mark the sides of the large square…” [21D]

“…we will calculate the area of the trapezoid…” [30B]

“…we will calculate the area of the rectangle…” [32B]

“…we will calculate the areas of the given rectangle…” [46B]

Verbal explanation

28.0% (N = 16)

Explanation The students related to the problem as a collection of areas and given geometrical figures. Areas were described as equal and overlapping and were “cut out” and moved around.

In order to find out who ate more, I tried to “put” the father’s pieces into  the son’s…” [22C]

Other

15.8% (N = 9)

“…I used the small square as a unit of measurement and reached the conclusion that the hearts were equal to 5 squares altogether…” [43D]