Cardinal numbers (1 to 1,000)

• 1 - one	11 - eleven	21 - twenty - one
  2 - two	12 - twelve	25 - twenty - five
  3 - three	13 - thirteen	30 - thirty
  4 - four	14 - fourteen	40 - forty
  5 - five	15 - fifteen	50 - fifty
  6 - six	16 - sixteen	60 - sixty
  7 - seven	17 - seventeen	70 - seventy
  8 - eight	18 - eighteen	80 - eighty
  9 - nine	19 - nineteen	90 - ninety
  10 - ten	20 - twenty	100 - one hundred

+ Todos los números entre el 21 y el 99 están conectados por un guión: 
21 - twenty-one 
42 - forty-two 

73 - seventy-three

+ Hundreds and tens are usually separated by 'and' (in American English 'and' is not necessary).

110 - one hundred and ten

101 - one hundred and one

350 - three hundred and fifty

+ Para expresar los millares, antes de la palabra "thousand" los números 1 a 999 se escriben por separado. "Thousand" se escribe siempre en singular.

1000 - one thousand

1,250 - one thousand, two hundred and fifty 

2,001 - two thousand and one