← Home
Number in Maths Flashcards
Free GCSE Maths Number Revision Cards
Brush up on fractions, decimals, indices, standard form, surds and prime factorisation with these free GCSE Maths flashcards. Covers the essential number skills for GCSE exam success.
Question
What is a prime number?
tap to flip
Answer
A number greater than 1 with exactly two factors: 1 and itself. Examples: 2, 3, 5, 7, 11, 13. Note: 1 is NOT a prime number.
tap to flip
Question
What is prime factorisation?
tap to flip
Answer
Expressing a number as a product of its prime factors. Example: 60 = 2² × 3 × 5. Used to find HCF and LCM.
tap to flip
Question
How do you find the HCF using prime factors?
tap to flip
Answer
Find the prime factorisation of both numbers, then multiply the common prime factors (using the lowest power of each).
tap to flip
Question
How do you find the LCM using prime factors?
tap to flip
Answer
Find the prime factorisation of both numbers, then multiply all prime factors (using the highest power of each).
tap to flip
Question
What are the rules for adding and subtracting fractions?
tap to flip
Answer
Find a common denominator, convert both fractions, then add/subtract the numerators. Keep the denominator the same.
tap to flip
Question
What are the rules for multiplying fractions?
tap to flip
Answer
Multiply numerators together and denominators together: (a/b) × (c/d) = ac/bd. Simplify before multiplying where possible.
tap to flip
Question
What are the rules for dividing fractions?
tap to flip
Answer
Flip the second fraction (take the reciprocal) and multiply: (a/b) ÷ (c/d) = (a/b) × (d/c).
tap to flip
Question
What is a recurring decimal and how do you convert it to a fraction?
tap to flip
Answer
A decimal that repeats indefinitely. To convert: multiply by a power of 10 to shift the pattern, then subtract the original — e.g. 0.̄3 = 1/3.
tap to flip
Question
What is standard form (scientific notation)?
tap to flip
Answer
A way of writing very large or small numbers: A × 10ⁿ, where 1 ≤ A < 10 and n is an integer. Example: 3,400,000 = 3.4 × 10⁶.
tap to flip
Question
What are the index laws?
tap to flip
Answer
aᵐ × aⁿ = aᵐ⁺ⁿ; aᵐ ÷ aⁿ = aᵐ⁻ⁿ; (aᵐ)ⁿ = aᵐⁿ; a⁰ = 1; a⁻ⁿ = 1/aⁿ; a^(1/n) = ⁿ√a.
tap to flip
🔒
See all 20 cards for free
Create a free account to unlock the full deck — no payment needed.