Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
4 courses
Irrational Numbers and Proofs
Mathematics · High School (9–10), General · Rational and Irrational Numbers
FreeCh 2 · 2/2
Why can the square root of 2 never be a fraction? Learn to prove it, step by step, with a proof by contradiction. Then prove the same for other roots, and find out when a sum or a product of such numbers is irrational.
3Lessons11Problems2Python Labs1Question Set1Mock Test
Primes, HCF and LCM
Mathematics · High School (9–10), General · Divisibility, HCF and LCM
FreeCh 2 · 1/2
Break any number into primes, and see why there is only one way to do it. Then use the primes to find the HCF and the LCM, and solve real problems with them: bells that ring together, the largest tile for a floor, and buses that meet again.
3Lessons11Problems2Python Labs1Question Set1Mock Test
Real Numbers: Operations and Exponents
Mathematics · High School (9–10), General · Exponents and Radicals, Rational and Irrational Numbers
FreeCh 1 · 2/2
What happens when you add or multiply an irrational number? How do you remove a square root from the bottom of a fraction? Here we learn the rules, we rationalise denominators, and we use the laws of exponents with fractional powers.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Rational and Irrational Numbers
Mathematics · High School (9–10), General · Rational and Irrational Numbers
FreeCh 1 · 1/2
A fraction can be written as a decimal that ends or repeats. Some numbers do not do either. In this course we learn to tell the two kinds apart, and we find irrational numbers such as the square root of 2 on the number line.
3Lessons10Problems2Python Labs1Question Set1Mock Test