Como se dicen los números en Ingles. Una guía inicial

Symbol	Word	Pronounce It
0	Nought	0
1	One	1
2	Two	2
3	Three	3
4	Four	4
5	Five	5
6	Six	6
7	Seven	7
8	Eight	8
9	Nine	9
10	Ten	10
11	Eleven	11
12	Twelve	12
13	Thirteen	13
14	Fourteen	14
15	Fifteen	15
16	Sixteen	16
17	Seventeen	17
18	Eighteen	18
19	Nineteen	19
20	Twenty	20
21	Twenty-one ...	21
30	Thirty	30
40	Forty	40
50	Fifty	50
60	Sixty	60
70	Seventy	70
80	Eighty	80
90	Ninety	90
100	One hundred	100
101	One hundred and one ...	101
102	One thousand	1,000
1,000,000	One million	1,000,000
1,000,000,000,000	One billion	1,000,000,000,000

Ordinal Numbers - used for ranking
In figures	In words	Pronounce It
1st	the first	1st
2nd	the second	2nd
3rd	the third	3rd
4th	the fourth	4th
5th	the fifth	5th
6th	the sixth	6th
7th	the seventh	7th
8th	the eighth	8th
9th	the ninth	9th
10th	the tenth	10th
11th	the eleventh	11th
12th	the twelfth	12th
13th	the thirteenth	13th
14th	the fourteenth	14th
15th	the fifteenth	15th
16th	the sixteenth	16th
17th	the seventeenth	17th
18th	the eighteenth	18th
19th	the nineteenth	19th
20th	the twentieth	20th
21st	the twenty-first	...
22nd	the twenty-second	...
23rd	the twenty-third	...
24th	the twenty-fourth	...
25th	the twenty-fifth	...
26th	the twenty-sixth	...
27th	the twenty-seventh	...
28th	the twenty-eighth	...
29th	the twenty-ninth	...
30th	the thirtieth	30th
40th	the fortieth	40th
50th	the fiftieth	50th
60th	the sixtieth	60th
70th	the seventieth	70th
80th	the eightieth	80th
90th	the ninetieth	90th
100th	the hundredth	100th
101st	the hundred and first	...
1000th	the thousandth	1000th

Ordinal numbers are often used in fractions:-

Fractions
Symbol	Word	Pronounce It
1/8	One eighth	1/8
1/5	One fifth
1/4	One quarter	1/4
3/4	Three quarters	3/4
1/3	One third	1/3
2/3	Two thirds
1/2	One half	1/2

Sums
Symbols	Word (common term in brackets)	Pronounce It
+	Plus (And)	+
-	Minus (Take away)	-
x	Multiplied by (Times)	x
÷	Divided by	÷
=	Equals (Is)	=
.	Point	.
%	Percent	%
(((1 + 6) - 2) x 2) ÷ 2.5=4	One plus six minus two multiplied by twodivided by two point five equals four or One and six take away two times twodivided by two point five is four	1 + 6 - 2 x 2 ÷ 2.5=4
10% 100=10	Ten percent of one hundred equals ten.	10% 100=10

What to say
We often say "a" instead of "one". For example when we have the numbers 100 or 1/2 we say "A hundred" or "A half". For example: 11/2 - "One and a half."
When pronouncing decimals we use the word point to represent the dot. The numbers following the dot are pronounced separately. For example: When you have the number 1.36 we say "One point three six."

Interesting Numbers
~ 0 ~ What could possibly be interesting about nothing? It's the number of ways you can say 0 in English.   When we use it For example:- 0 = oh after a decimal point 9.02 = "Nine point oh two."   in bus or room numbers Rooom 101 = "Room one oh one." Bus 602 = "Bus six oh two."   in phone numbers 9130472 = "Nine one three oh four seven two."   in years 1906 = "Nineteen oh six." 0 = nought before a decimal point 0.06 = "Nought point oh six." 0 = zero in temperature -10°C = "10 degrees below zero."   US English for the number 0 = "Zero" 0 = nil in football Chelsea 2 Manchester United 0 = "Chelsea two Manchester United nil." 0 = love in tennis 20 - 0 = "Twenty love."
~ 12 ~ The number 12 is often represented as a dozen and the number 6 as a half dozen. For example: 12 eggs= "A dozen eggs." 6 eggs = "Half a dozen eggs."^
~ 13 ~ A dozen is 12, but a baker's dozen is 13, because in the past bakers who were caught shortchanging customers could be liable to severe punishment, so they used to add an extra bread roll to make up the weight.
~ 1 billion ~ When is a billion not a billion? In British English billion traditionally means a million million = 1,000,000,000,000 = 1012 In American English billion means a thousand million = 1,000,000,000 = 109 The American billion has become standard in technical and financial use. However, to avoid confusion it is better to use the terms "thousand million" for 109 and "million million" for 1012. Milliard " is French for the number 109. It is not used in American English but is sometimes, but rarely, used in British English.
Letters as Numbers
~ k ~ The letter k is often used to denote a thousand. So, 1k = 1,000. If you see a job advertised and it offers a salary of £12k it means £12,000.00.
~ m ~ The letter m is often used to denote a million. So, 1m = 1,000,000. If you see a job advertised and it offers a salary of £12m, apply for it!
~ bn ~ The letters bn denote a billion. So, 1bn is usually 1,000,000,000 (see above). If you see a job advertised and it offers a salary of £12bn, it's probably a missprint.