5 resources.
Quick tests to check whether a number is divisible by 2 through 12, with worked examples.
Squares from 1 to 30 and cubes from 1 to 20, with last-digit patterns, mental squaring shortcuts, and how to find square and cube roots of perfect powers.
Finding HCF using Euclid's division algorithm and prime factorization, plus verifying LCM x HCF = product of two numbers, with worked examples.
Proving a number is irrational by contradiction, and telling whether a fraction has a terminating or repeating decimal expansion, with worked examples.
Prime numbers up to 100, why 0 and 1 aren't prime, checking primality up to the square root, prime factorization and distinct prime factors, twin and co-primes, and common mistakes.