Data Representation — O/L Mathematics

What must I remember about Data Representation?

• Pie charts represent component data as sectors of a circular disk proportional to their frequencies: Sector angle = (Frequency / Total frequency) × 360°.
• Determining component value from sector angle: Value = (Sector angle / 360°) × Total frequency.
• Bar charts represent categorical frequencies using discrete rectangular columns of uniform width with equal spacing between columns.
• Histograms represent continuous grouped numerical data using contiguous rectangular bars whose areas are proportional to class frequencies.
• Frequency polygons connect the midpoints of the tops of histogram bars to display overall distribution profile.

Test yourself (1 minute)

1. The 360° total validation

   The sum of all calculated sector angles in a pie chart MUST equal exactly 360°; check your angle arithmetic before drawing.

2. Protractor precision in Paper 1 Part B & Paper 2

   Align the protractor origin precisely with the circle centre and baseline; inaccurate angles lose plotting marks.

3. Label every sector

   Every sector in a pie chart must clearly display its category name and calculated angle or frequency.

Practise Data Representation questions today

Source: NIE G.C.E. (O/L) Mathematics Syllabus (Grade 10, Unit 10)

What should I study first?

Next in the syllabus

Where does Data Representation fit in the syllabus?

Grade 10 · Term 1