Non-Calculator Techniques for IGCSE Maths
From 2025, Papers 1 and 2 are non-calculator. These techniques will help you work efficiently without a calculator.
Mental Arithmetic
Know times tables to 12×12 fluently. Memorise squares up to 15² and cubes up to 5³. Know common fraction-decimal conversions.
Tips
- 1/8=0.125, 1/3=0.333, 1/6=0.167
- 25×anything: halve then ×50
- Practice 5 minutes daily
Estimation
Round each number to 1 significant figure before calculating. This gives quick approximations to check your exact answers.
Tips
- Round to 1 s.f. for estimates
- 3.7 × 9.2 ≈ 4 × 9 = 36
- Use estimation to verify exact answers
Fraction Shortcuts
Find common denominators using LCM. Cancel before multiplying fractions. Convert mixed numbers to improper fractions first.
Tips
- Cancel diagonally when multiplying
- LCD = LCM of denominators
- Check: is your answer reasonable?
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Is this relevant for the 2025 syllabus?
Yes, all content is aligned with the Cambridge IGCSE Mathematics 0580 syllabus for 2025-2027.
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