Math & Numbers Facts for Kids
Mind-bending number facts
A butterfly's wings display reflective symmetry β one side is a mirror image of the other. Mathematicians study symmetry using a branch of maths called group theory.
The coordinate grid used in maths, with x and y axes, was invented by French mathematician RenΓ© Descartes in the 17th century. It is named the Cartesian coordinate system in his honour.
The sum of all whole numbers from 1 to 100 is 5,050. The young mathematician Carl Friedrich Gauss reportedly solved this in seconds as a schoolboy by noticing that pairs like 1 and 100 each add to 101.
One mile is approximately 1.609 kilometres. A quick mental trick for converting miles to kilometres is to multiply by 1.6, or use the Fibonacci sequence β consecutive Fibonacci numbers are very close to the miles-to-kilometres ratio.
The oldest known counting tally marks are carved into a baboon's fibula bone found in Swaziland and are around 43,000 years old. This suggests humans were counting long before writing was invented.
In the branch of maths called topology, a coffee cup and a doughnut are considered the same shape because each has exactly one hole. Topology studies properties that are unchanged by stretching or bending.
Speed, distance, and time are connected by the formula: distance = speed Γ time. Covering up the variable you want to find in the triangle gives you the formula to calculate it.
On a hundred square grid (1 to 100), multiples of any number form a regular diagonal or column pattern. Mathematicians use these patterns to help find prime numbers using the Sieve of Eratosthenes.
Compound interest means earning interest on your interest, causing savings to grow faster and faster over time. Albert Einstein reportedly called it 'the eighth wonder of the world'.
There are exactly five regular polyhedra, known as the Platonic solids: the tetrahedron, cube, octahedron, dodecahedron, and icosahedron. Plato believed they represented the four elements and the cosmos.