• number
A number is a count or measurement. It is really an idea in our minds. ○ count: the total determined by counting ○ measurement: the size, length or amount of something, as established by measuring
5148#9577 SIBLINGS CHILDREN 9577

• 0750± positional notation
By the 8th century, Indian mathematicians had perfected positional notation and over the next several centuries, Arab merchants, scholars and conquerors began to spread it into Europe. -- vigesimal, Maghreb, Hebrew, glyph, Aztecs, duodecimal, sexigesimal
5148#4984 SIBLINGS CHILDREN 4984

• 1202 Leonardo Fibonacci
Fibonacci asked himself how many pairs of rabbits originated from a single pair in one year. Each pair of rabbits will produce exactly one more pair of both sexes per month which in turn would be fertile from the second month after birth.
5148#4759 SIBLINGS CHILDREN 4759

• 1545 Gerolamo Cardano
5148#9541 SIBLINGS CHILDREN 9541

Pillow English Listening

• 1571 - 1630 Johannes Kepler
Keplar observed that the relationship between a number in Fibonacci sequence and the previous number more and more closely approaches the irrational number Φ the longer the sequence is continued and Φ describes nothing other than the golden section.
5148#5056 SIBLINGS CHILDREN 5056

• 1643 - 1727 Isaac Newton
Galileo had already discovered some years prior that the distance traveled by a falling object is represented by a function of time. Newton wondered how one could calculate the velocity of the object at any particular instance during the fall.
5148#5035 SIBLINGS CHILDREN 5035

• 1646 - 1716 Gottfried Wilhelm Leibniz
Leibniz did similar work just a few years later, independently of Newton, and it is actually his notation that we still use today.
5148#5027 SIBLINGS CHILDREN 5027

• 1707.1783 Leonhard Euler
5148#9670 SIBLINGS CHILDREN 9670

• 1843 Quaternion
5148#9654 SIBLINGS CHILDREN 9654

• 1900± Crisis in Mathematics
Gottlob Frege, Bertrand Russel, Alfred North Whitehead, Zermelo-Fraenkel, Dedekind, Ernst Snapper
5148#4835 SIBLINGS CHILDREN 4835

• BC 0300? Euclid
It was the Greek mathematician Euclid who produced the first precise description of the golden section. A length is devided into two parts in such a way that the smaller part is to the larger part in the same proportion as the larger one is to the whole.
5148#5055 SIBLINGS CHILDREN 5055

• BC 0500? Hippasus
According to Pythagoras theorem the diagonal length of a square with each side measuring one unit would be square root of two. The assumption that square root of two could be expressed as a ratio of two integers deduces a contradiction.
5148#5026 SIBLINGS CHILDREN 5026

• BC 0500? rational numbers
5148#5017 SIBLINGS CHILDREN 5017

• BC 0570 - 0495 Pythagoras
○ How many ways are there to prove the Pythagorean theorem? - Betty Fei ○ James Garfeild, Pythagoras, hypotenuse, tessellation, Euclid
5148#5039 SIBLINGS CHILDREN 5039

• BC 0600 Pythagoras
5148#3783 SIBLINGS CHILDREN 3783

• BC 0800? Roman Numerals
The Romans showed numbers into the thousands using these 7 symbols: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500 and M for 1000.
5148#5164 SIBLINGS CHILDREN 5164

◌◌◌ dimension
The number of dimensions is how many values are needed to locate points on a shape.
5148#9579 SIBLINGS CHILDREN 9579

• How Far Mathematical Foundations
5148#5331 SIBLINGS CHILDREN 5331

• Map of Mathematics
5148#9551 SIBLINGS CHILDREN 9551

• The Great Math Mystery
5148#9620 SIBLINGS CHILDREN 9620

• Types of Numbers
a divine perfection, all hell broke loose, survey, taxonomy
5148#9547 SIBLINGS CHILDREN 9547