Anomalies in the number of sex chromosomes Illustration Play

Antimatter Animation Play

Apparent weightlessness Student activity Play

Apparent weightlessness Whiteboard exercise Play

Application of graphs Animation Play

Application of Harry's formula Whiteboard exercise Play

Applying proportion Student activity Play

Applying the trapezium rule for a different number of sub-intervals Whiteboard exercise Play

Approximating irrational numbers Student activity Play

Approximating square root of three Whiteboard exercise Play

Approximating square root of two Whiteboard exercise Play

Approximating surds Student activity Play

Approximating surds Animation Play

Approximation error and the number of sub-intervals Simulation Play

Approximation of the number e Whiteboard exercise Play

Approximations of irrational numbers Whiteboard exercise Play

Approximations of irrational numbers Student activity Play

Archimedes' Experiment Whiteboard exercise Play

Archimedes' Experiment Student activity Play

Are all atoms of the same element identical? Student activity Play

Arithmetic mean Animation Play

Arithmetic mean – 'balancing point' of the data Student activity Play

Arrangements Student activity Play

Assigning electrons to atomic orbitals Student activity Play

Astronomical numbers Animation Play