English — numbers 13–100

The teens, the tens and one hundred — how to keep counting past twelve.

Three things to watch: 13–19 end in -teen, but thirteen and fifteen change the stem (not “threeteen”, “fiveteen”); the tens 20–90 end in -ty, and forty is spelt without a u (not “fourty”); compound numbers take a hyphen, with the ten first: twenty-one, ninety-nine.

numbers 13–100
Number	Word
13	thirteen
14	fourteen
15	fifteen
16	sixteen
17	seventeen
18	eighteen
19	nineteen
20	twenty
30	thirty
40	forty
50	fifty
60	sixty
70	seventy
80	eighty
90	ninety
100	one hundred