Los números desde el punto de vista gramatical son adjetivos numerales y pueden

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1 FIRST TOPIC: NUMBERS UNIT 1.CARDINAL AND ORDINAL Los números desde el punto de vista gramatical son adjetivos numerales y pueden aparecer de dos formas, como números cardinales y como números ordinales. A) CARDINAL NUMBERS (números para contar / counting numbers /numbers used for counting / to count) 0 Nought, zero one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty A partir del 20 Las unidades se separan de las decenas por un guión. 21 twenty-one 30 thirty 40 forty 50 fifty 60 sixty 70 seventy 80 eighty 90 ninety 100 one hundred 101 one hundred and one 1000 one thousand 1001 one thousand and one En un número de tres cifras one hundred, two hundred, van siempre seguidos de and. 123 one hundred and twenty-three Los millares no se unen a las centenas ni con guión, ni con and, ni con coma one thousand three hundred and fifty Si el lugar de las centenas lo ocupa un cero, los millares van seguidos de and three thousand and eighty-one Los números de cuatro cifras, especialmente las fechas pueden leerse por parejas 1975 nineteen seventy-five

2 Los números de cuatro cifras terminados en dos ceros, pueden leerse con las dos primeras cifras seguidas de hundred 2500 twenty-five hundred En lenguaje coloquial, hundred, thousand and million suelen ir precedidos de a en lugar de one a hundred a thousand a million Hundred, thousand and million, cuando van precedidos de otro número o determinante numeral, o sea, cuando funcionan como adjetivos, no llevan s final en el plural En cambio si funcionan como sustantivos si termina en s el plural. Doscientos dolares: Two hundred dollars Miles de pajaros : Thousands of birds En Inglés, se utiliza una coma ó un espacio para marcar los millares (nunca un punto como nosotros) 25, El cero: 0 nought zero o nothing nil love mathematical digits point zero, zero degrees telephone numbers coloquial In football In tennis B) ORDINAL NUMBERS (números para ordenar/ arranging numbers / numbers used for arranging / to arrange) first second third fourth fifth sixth seventh eightth ninth tenth eleven twelf thirtee fourtee fifteen sixteen seventee eightee ninetee twenti th th nth nth th th nth nth nth eth

3 Twenty Thirtiet Fourtiet Fiftiet Sixtiet Seventiet Eightiet Ninetiet -first h h h h h h h One hundredt h One hundre d and first 1000 One thousandth 1001 One thousand and first One millionth Los números ordinales se abrevian añadiendo al número cardinal correspondiente las dos últimas letras de dicho ordinal. 1º _1 st 2º _2 nd 3º_ 3 rd 4º_ 4 th 18º_ 18 th Situaciones en las que se utilizan números ordinales DATES_ 1st April, 1 st of April, April the 1 st, April 1st TITLES_ Isabel II Elisabeth II Elisabeth the second PRIZE_ The first prize, the 2 nd prize, CENTURY_ 21stcentury, 18 th century,. CLASIFICATIONS_ The 4 th position El primero y el último EL PRIMERO_THE FIRST EL ÚLTIMO_ THE LAST EL SEGUNDO_ THE SECOND EL PENÚLTIMO_ THE SECOND LAST EL TERCERO_ THE THIRD EL ANTEPENÚLTIMO_ THE THIRD LAST

4 NUMBERS Numbers are the basic buliding blocks of mathematics. Some numbers share common properties and can be grouped together in SETS. Digit: any of the ten (Hindu-arabic) numbers: 0,1,2,3,4,5,6,7,8,9 Number system: The base ten number system is the more usual today. Dou you know another one that we use? The binary system or base two number system The roman system The sexagesimal system Place value. In our system the value of a digit is relating to its position. thousands hundreds tens units Decimal tenths hundreths thousandths point Sets of numbers How many different kinds of numbers do you know?

5 Natural, N Natural numbers are the counting numbers {1, 2, 3,...} (positive integers) or the whole numbers {0, 1, 2, 3,...} (the non-negative integers). Mathematicians use the term "natural" in both cases. Integer, Z Integers are the natural numbers and their negatives together with zero {... 3, 2, 1, 0, 1, 2, 3,...}. (Z is from German Zahl, "number".) Rational, Q Rational numbers are the ratios of integers, also called fractions, such as 1/2 = 0.5 or 1/3 = Rational decimal expansions end or repeat. (Q is from quotient.) Irrational Number, I Real number that cannot be written as a simple fraction. Irrational means not Rational Examples: Real, R The set of all rational and irrational numbers A simple way to think about the Real Numbers is: any point anywhere on the number line (not just the whole numbers). Examples: 1.5, -12.3, 99, 2, π They are called "Real" numbers because they are not Imaginary Numbers MORE ABOUT NUMBERS Number line Consecutive numbers Numbers that are next to each other Positive number: above zero Negative number: below zero Even number: Any integer that can be divided by 2 without leaving a remainder Odd number: any integer that cannot be divided by 2 without leaving a remainder

6 ARITHMETIC is the ability to use NUMBERS. The four basic operations used in calculations are: ADDITION, SUBTRACTION, MULTIPLICATION and DIVISION. ADDITION = 11 five plus six equal to eleven SUBTRACTION 6 1 = 5 six minus one equal to five MULTIPLICATION 6 X 8 = 48 six times eight equal to forty-eight You can also say: six multiplied by eight is equal to forty-eight 6 and 8 are called FACTORS and 48 is the PRODUCT DIVISION 40 : 8 = 5 fourty divided by eight equal to five 40/8= 5 40 =5 this is a división without remainder. It s exact 8 MIXED OPERATIONS (7-5) =14 POWER 2 3 = 8 2: base 3: index or exponent We can express 8 in power form as 2 3 The squares are raised to the power of two/the second power The cubes are raised to the power of three/the third power THE SQUARE ROOT Take the square root of 50 THE CUBE ROOT Take the cube root of 8