matematika



Measurements for Length, Weight and Time.
Digits - Roman Arabic.

Necessities of life made people not only count but measure. At first for measuring length were used the step, the elbow or the span, but these measurements are inaccurate, in different people they have different size. In the end of the 18th century in France was created the metrical measure system. Scientists took for a unit segment which contains 10,000,000 times in the quarter meridianial circumference. They called it meter.

For basic measure for weight was taken the gramme, which is equal to 1 cubic centimeter water filtered at 4 degrees.

The most used measure for weight is the kilograms.

Table for measures of length. Basic unit – meter(m)

Partitions
NameCancellationContains metersNameCancellation1m contains
Decameterdkm10Decimeterdm10dm
Hectometerhm100Centimetercm100cm
Kilometerkm1000Millimetermm1000mm

Table for measures of weight. Basic unit – gramme(g)

Cancellation
NameCancellationContains grammesNameCancellation1gramme contains
Decagramdkg10Decigramdg10dg
Hectogramhg100Centigramsg100sg
Kilogramkg1000Milligrammg1000mg

Measures for weight are also centner(c) = 100kg and tone(t) = 1000kg

Measures for time

Basic measures for time are the day and the year. Other measures are: the hour , the minute and the second.

For one day (24hours) the Earth spins one time ( from west to the east) around its axis. For one year the planet goes around the sun. According to the estimations of the astronomers the Earth goes around the sun for 365 days 5 hours 48 minutes and 46 seconds

In our every day life we count the year only with the full 365 days. Such year is called usual. For 4 years the missed 5 hours 48 minutes and 46 seconds form approximately 1 day, which is added to the 365 days and than the year has 366 days. Such year is called leap year.

1 century = 100 years
1 year contains 12 months
1 usual year contains 365 days
1 leap year = 366 days
1 month contains 30 or 31 days, February contains 28 or 29 days, depends if the year is usual or not
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 week = 7 days

Digits - Roman Arabic

Signs which we use to write down numbers are called digits.
There are 10 Arabic digits: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.
With the help of those digits every number can be written.
Numbers which we write with 1 digit are called one-digit numbers. For example 7;3;5 etc

Numbers which we write with 2 digits - two-digit numbers. They contain ones and tens. Leftward digit is the tens. For example 25;37;

To the class of simple digits belong - ones, tens, hundreds .
Class of thousands .
Class of millions .
Class of milliards .
Number 75760914307 we read like this - 75 milliards 760 millions 914 thousands and 307

Except Arabic in practice we use Roman digits too.
Roman digits are seven
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000
There is no 0 in the Roman digits.


Send us math lessons, lectures, tests to:

  Math Bookstore   Questions and Answers
Copyright © 2005-2013.