Calculation of percentages
Did you know ? Archimedes is considered the discoverer of density and Archimedes' law of buoyancy of a body in a liquid, which he discovered while taking a bath, after which he ran naked into the street shouting "eureka" - I found it. He described an irrigation device that is still called Archimedes' screw. He introduced the concept of center of gravity and calculated the center of gravity of various geometric shapes.

Calculation of percentages

Percentage increase

Percentage change

Direct proportion

Indirect proportionality

Share in percentage

Profit from interest

Price without VAT

Price with VAT

Trade margin


Discount in percentage

Geometric calculations
Did you know ? Nikolay Ivanovich Lobachevsky was a Russian mathematician, co-creator of non-Euclidean geometry: Lobachevsky's geometry has the same axioms as Euclidean geometry, except for the axiom about parallel lines. In Lobachevski's geometry, it is postulated that through a point that does not lie on the line a, it is possible to draw at least two straight lines that do not intersect the line a in the given plane determined by this point and the line (it follows from this that there are infinitely many of them).

Center of the triangle

Angles of a triangle







Sphere segment



Circular segment

Physics calculations
Did you know ? Niels Bohr (1885-1962) - Danish physicist who created a model of the atom that helped explain the properties of chemical elements and electromagnetic radiation.

Newton's law of motion

Work done by a force

Kinetic energy

Gravitational field

Conservation of momentum

Newton's second law

Oscilating object

Law of Gravity

Snell's law of refraction

Electric potential

Ohm's law

Coulomb's law


Albert Einstein

Isaac Newton

Charles Darwin

Galileo Galilei

Nikola Tesla

Marie Curie

Stephen Hawking

Richard Feynman

Johannes Kepler

Louis Pasteur

Thomas Alva Edison

Alan Turing

James Clerk Maxwell

Werner Heisenberg

Erwin Schrödinger

Blaise Pascal


Niels Bohr