GCSE Maths Revision Guide
Frequency Polygons
Read and interpret frequency tables and calculate averages from grouped data. This free GCSE Maths module combines short explanations, worked examples, flashcard-style recall, and timed practice so students can revise the topic without creating an account.
Foundation Skills
Reading Frequency Tables
A frequency table shows how often each value or range occurs. Total frequency = total number of data items.
Midpoint
For grouped data, use the midpoint of each class to estimate the mean.
Formula: Midpoint = (lower + upper) / 2
Example: Class 10-20: midpoint = 15
Higher Skills
Estimated Mean from Grouped Data
Multiply each midpoint by its frequency, sum these, then divide by total frequency.
Formula: Mean ā Ī£(fx) / Ī£f
Example: Scores 0-10 (f=3), 10-20 (f=7): Ī£fx = 5Ć3 + 15Ć7 = 120 Mean = 120/10 = 12