The unknown on both sides of the equation Student activity Play

The unknown on one side of the equation Whiteboard exercise Play

The unknown on one side of the equation Student activity Play

The unknown on one side of the equation – more difficult problems Student activity Play

The unknowns Whiteboard exercise Play

The value of the number m Whiteboard exercise Play

The vector equation of a line Animation Play

The weight of one lemon Animation Play

Theorems and their assumptions in algebra Whiteboard exercise Play

Theorems and their assumptions in algebra Student activity Play

Theorems and their assumptions in geometry Student activity Play

Thermal resistance Animation Play

Thermal resistance Student activity Play

Thermal resistance Animation Play

Thermal resistance Whiteboard exercise Play

Think of a number Whiteboard exercise Play

Think of a number Student activity Play

Time needed to cut some amount paper Whiteboard exercise Play

Time needed to do the work Student activity Play

Time needed to wash potatoes Whiteboard exercise Play

Transformation of an equation into a quadratic equation Whiteboard exercise Play

Transformation of an equation into a quadratic equation Student activity Play

Transforming the equation of the circle Whiteboard exercise Play

Transforming the equation of the circle Whiteboard exercise Play

Transforming the vector equation of a line Animation Play