Subtracting fractions – practical problems Student activity Play

The ecosystem – an organized and functional unit of the natural environmental Whiteboard presentation Play

The ecosystem – an organized and functional unit of the natural environmental Class activity Play

The first tangent theorem – perpendicularity Student activity Play

The influence of environmental factors on sex determination Animation Play

The nervous system as a receptor of environmental stimuli Class activity Play

The nervous system as a receptor of environmental stimuli Whiteboard presentation Play

The ratio of two values – more difficult problems Student activity Play

The sum of a finite geometric series – problems Whiteboard exercise Play

The sum of a finite geometric series – problems Student activity Play

The sum of a finite geometric series – problems Whiteboard exercise Play

The tangent theorem – solving problems Whiteboard exercise Play

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

Trigonometric ratios – problems Student activity Play

Typical problems with quadratic equations Whiteboard exercise Play

Typical problems with quadratic equations Student activity Play

Using linear equations to solve practical problems Student activity Play

Using the factor form of the function in solving geometric problems Whiteboard exercise Play

Vision problems Slideshow Play

Wastes and their harmful effects Student activity Play