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Math Concepts Summary

Jun 16, 2025

Overview

This lecture summarizes solutions and key concepts from an AQA GCSE Maths Foundation past paper, focusing on clear methods and concise reasoning for each question.

Basic Calculations & Conversions

  • 0.02 × 100 = 2.
  • X + X + X = 3X.
  • 260 millimeters = 26 centimeters.
  • -8 × 5 = -40.
  • 4 apples at 35p each = £1.40; remaining £2.30 split across 5 bananas = 46p each.

Geometry & Symmetry

  • A trapezium can have all sides different lengths.
  • Triangle angles sum to 180°; exterior angle on straight line = 100°.
  • Rotational symmetry of order 4: shape repeats 4 times in 360°.

Data & Ratios

  • Pictograms: 1 circle = 4; total homework = 39 pieces, 19h 30m total time.
  • Mini-bus problem: 159 passengers need 14 mini-buses (each with 12 seats).
  • Tally chart criticisms: overlapping groups, not all data accounted for.
  • Probability: missing probability = 0.45.
  • Password ratio: numbers:letters:symbols = 1:3:2.

Algebra & Expressions

  • Combine like terms: 6A - 7B - 2A = 4A - 7B, but if negative two, adjust accordingly.
  • Index law: multiply numbers, add powers (3p² × 5p⁷ = 15p⁹).
  • Solve: 5x + 6 > 3x + 15 → x > 4.5.

Fractions & Percentages

  • Add fractions: common denominator, 5/6 + 1/4 = 17/12 = 1 5/12.
  • Percentages: 43% of 2100 = 903.

Graphs & Slopes

  • Fixed charge = 20p; gradient (cost per minute) = 8p.
  • 7 minutes call: 20p + (8p × 7) = 76p.

Statistics & Averages

  • Toffees median = 51 (above 50); mints median = 49 (not above 50).

Standard Form & Calculations

  • 2,000 × 70,000 = 1.4 × 10⁸ (standard form).
  • (1.8 × 10²) ÷ (3 × 10⁻¹) = 600 (ordinary number).
  • Prime factors: 200 = 2³ × 5².

Worded & Multi-step Problems

  • Reciprocal graph: y = 1/x.
  • Distance problem: total AD = 49 miles.
  • Trigonometry (sin 30°): x = 10 × 0.5 = 5 m.
  • Factorize: x² + 7x + 10 = (x + 5)(x + 2).

Key Terms & Definitions

  • Rotational Symmetry — Shape appears the same more than once as it rotates through 360°.
  • Tally/Frequency Chart — Method for grouping and counting data occurrences.
  • Index Law — When multiplying, add exponents.
  • Median — Middle value in an ordered data set.
  • Standard Form — Number written as a × 10ⁿ.
  • Prime Factors — Prime numbers that multiply to give the original number.

Action Items / Next Steps

  • Practice more past papers under timed, non-calculator conditions.
  • Review key formulas: trigonometry, standard form, percentages, and index laws.
  • Check criticisms and improvements for presenting data.