My Science School

  

               Infinity is a number, or value, which is so huge that it cannot be measured. For instance, the distance to the end of the Universe is called infinity, because if there is an end, it is so far away that it could never be measured.

               Sometimes infinity can be the result of a mathematical calculation. For example, the formula for calculating the distance around the outside of a circle is pi times the diameter. Pi is a Greek letter, and it represents a value of approximately 3.14159. Pi can never be fully calculated, because you would finish up with a string of numbers extending to infinity.

Picture credit: google

 

                    Geometry is a part of mathematics that deals with the shape, position and size of things of geometric forms such as squares, triangles, cubes and cones. Its name comes from the Greek words meaning ‘earth measuring’, because it was probably originally invented as a means of surveying and measuring land.

                   The ancient Egyptians also used geometry when constructing buildings and tombs. Nowadays, geometry is important to engineers and architects. It is also essential in navigation because geometry is used to follow charts and maps.

Picture credit: google

               Our numbers are called Arabic numerals, although they probably appeared first in India around AD600. By the 800s the Arab numbering system was use throughout Europe because it was much easier to use than the old Roman system. At first the numbers varied in the way they were written, but with the invention of printing the numbers became standardized. The basic Arab numbers are 0 to 9, and can be used to write any combination of numbers.

Picture credit: google

   

                 In some ways, Roman numbering worked like the modern Arabic numeral system where, starting from the left, there are thousands, hundreds, tens and individual units. However, Roman numerals are quite different. One thousand is written as M, five hundred as D, one hundred as C, fifty as L, ten as X and five as V.

               The decimal system describes a numbering system for calculation based on multiples of ten. Multiplying or dividing a number by ten is very easy because only the decimal point needs to be moved. In the decimal system, each number has a value ten times that of the next number to the right. For instance, 5,283 means five thousands, two hundreds, eight tens and three ones. The decimal point simply separates the main number from numbers less than one. The number ten has always been important in mathematics — you can easily count it on your fingers.

Picture credit: google

               The metric system is a group of various units of measurement. Its name comes originally from the metre. It is a decimal system, which means that each unit is ten times bigger, or smaller, than the next unit. Previously, measurements were difficult to calculate; in measurements of length, for example, there were 12 inches in one foot and three feet in one yard, while weight was calculated using ounces and pounds (16 ounces in one pound).

               The metric system was devised in the 1790s in France, and is now used in most countries in the world for all scientific and technical measurements.

Picture credit: google

               Numbers are used to describe the amount of things. We can express numbers in words, by hand gestures or in writing, using symbols or numerals. When we talk about a number we use words (‘five’) rather than the numeral (5), but when we write we use both words and numerals.

               Numbers can describe how many objects there are or their position among lots of objects, such as 1st or 5th for example. Other types of numbers describe how many units of something there are, for example how many kilograms (weight) or metres (length).Numbers are just a convenient way to describe ideas.

Picture credit: google