Numbers in Indo-European

Here are the names of the numbers from 1 to 10 in several different Indo-European languages.

English	one	two	three	four	five	six	seven	eight	nine	ten
German	eins	zwei	drei	vier	fünf	sechs	sieben	acht	neun	zehn
Swedish	ett	två	tre	fyra	fem	sex	sju	åtta	nio	tio
Norwegian	en	to	tre	fire	fem	seks	syv	åtte	ni	ti
French	un	deux	trois	quatre	cinq	six	sept	huit	neuf	dix
Italian	uno	due	tre	quattro	cinque	sei	sette	otto	nove	dieci
Spanish	uno	dos	tres	cuatro	cinco	seis	seite	ocho	nueve	diez
Portuguese	um	dois	três	quatro	cinco	seis	sete	oito	nove	dez
Catalan	un	dos	tres	quatre	cinc	sis	set	vuit	nou	deu
Latin	unus	duo	tres	quattor	quinque	sex	septem	octo	novem	decem
Russian	odin	dva	tri	chetyre	pyat'	shest'	sem'	vosem'	devyat'	desyat'
Polish	jeden	dwa	trzy	cztery	pięć	sześć	siedem	osiem	dziewięć	dziesięć
Welsh	un	dau	tri	pedwar	pump	chwech	saith	wyth	naw	deg
Greek	eîs	dúo	treiîs	téssares	pénte	hex	heptá	októ	ennéa	déka
Sanskrit	ekab	dvi	trayah	chatvarah	pancha	shash	sapta	ashta	nava	dasha

Even though several linguistic families such as Germanic (English, German, Swedish, and Norwegian), Romance (French, Italian, Spanish, Portuguese, Catalan, and Latin), Slavonic (Russian and Polish), Celtic (Welsh) and Greek are represented here, the words for the numerals 1 to 10 are quite similar in all of those languages. All of these languages are Indo-European languages, and are descended from one original language (called Indo-European), which is the ancestor of most modern European and Indian languages, Latin, Greek, Sanskrit, and other languages.

Indo-European has been reconstructed, and the following are the Indo-European words for the numerals 1 through 10, as well as 100 and 1000. Notice the similarities between these words (at least the words for 1 through 10) and all of the words above:

one	oinos
two	dwo
three	trejes
four	qetwor
five	pempe
six	sweks
seven	septm
eight	okto
nine	newn
ten	dekm
hundred	kmtom
thousand	sm-gheslom

See also some other word-related mathematical recreations.