We're designing a fictitious version of the Finish language, as it is spoken on the fictitious planet AntiEarth. Let's start with numerals one to ten. What will the numbers be?

yksi
kaksi
kolme
neljä
viisi
kuusi
seitsemän
kahdeksan
yhdeksän
kymmenen

Very good, except those are actually Finish. We want different numbers for a new version of Finish. They should sound kind of like Finish, but be totally different.

Okay, let's try some Anti-Earth Finnish numerals.
I'll aim for sounds inspired by Finnish phonology, but completely new words:

harsi
kela
tolmi
neva
viita
kuusko
seitsa
kahdeksu
yhdeksu
kymppi (This one is close to Finnish, but I like the -ppi ending for ten.)

I like how those sound, too. If kymppi is ten, and -ppi is the ending for ten, what are numbers twenty, thirty, forty, etc in AntiMaan keiliä ?

Good question! Let's build on that -ppi ending for tens.
Here's a possible system for the Anti-Earth Finnish tens:

20: kakskymppi (two-ten)
30: kolmekymppi (three-ten)
40: neljäkymppi (four-ten)
50: viitakymppi (five-ten)
60: kuuskokymppi (six-ten)
70: seitsakymppi (seven-ten)
80: kahdeksukymppi (eight-ten)
90: yhdeksukymppi (nine-ten)
100: sata (This can remain the same or be something new like saatta)
This keeps the base numbers and adds the "-kymppi" suffix, similar to how Finnish works with "-kymmenen."
It's consistent and pronounceable within the established sound patterns.

Yes, but you used actual Finnish kaks, kolme, etc, instead of AntiEarth kela, tolmi, etc.

You are absolutely right!
My apologies.
Let's correct that.
Here are the Anti-Earth Finnish tens,
using the Anti-Earth base numbers we created:

20: kelakymppi
30: tolmikymppi
40: nevakymppi
50: viitakymppi
60: kuuskokymppi
70: seitsakymppi
80: kahdeksukymppi
90: yhdeksukymppi
100: sata (or saatta)
That's much better!  Thanks for catching that.

I want to change sata. I suggest tippsa, derived from St Tibs day on the Discordian Calandar. Make that change, and then count from 98 to 103.

Excellent suggestion!
"Tippsa" sounds suitably otherworldly.
Let's incorporate that and count from 98 to 103 in Anti-Earth Finnish:

98: yhdeksukymppi kahdeksu
99: yhdeksukymppi yhdeksu
100: tippsa
101: tippsa harsi
102: tippsa kela
103: tippsa tolmi
And so on.
"Tippsa" works nicely as the new word for one hundred.

Jummi Tuumi! That means "Very Good" in AntiEarth language. So now count from 997 to 1003, and if you get it right, then say "Very Good", all in AntiEarth!

Here's the count from 997 to 1003 in Anti-Earth Finnish:

997: tippsa yhdeksukymppi seitsa
998: tippsa yhdeksukymppi kahdeksu
999: tippsa yhdeksukymppi yhdeksu
1000: tippsa
1001: tippsa harsi
1002: tippsa kela
1003: tippsa tolmi
Jummi Tuumi!

Almost, but tippsa is 100, not 1000. I forgot to tell you that 1000 in AntiEarth is written like this: დუმპსტადუმპსტა

You're absolutely right! My apologies.  I got carried away with tippsa and forgot the new word for 1000.  Let's try that again, correctly this time:

997: tippsa yhdeksukymppi seitsa
998: tippsa yhdeksukymppi kahdeksu
999: tippsa yhdeksukymppi yhdeksu
1000: დუმპსტადუმპსტა
1001: დუმპსტადუმპსტა harsi
1002: დუმპსტადუმპსტა kela
1003: დუმპსტადუმპსტა tolmi
Jummi Tuumi!

Very nice, but there is still one small problem. 900 is yhdeksutippsa, not tippsa.

You are absolutely correct!
My brain is getting stuck on the tippsa and not thinking through the full construction.
Let me try that one more time, with the proper 900 and 1000:

997: yhdeksutippsa yhdeksukymppi seitsa
998: yhdeksutippsa yhdeksukymppi kahdeksu
999: yhdeksutippsa yhdeksukymppi yhdeksu
1000: დუმპსტადუმპსტა
1001: დუმპსტადუმპსტა harsi
1002: დუმპსტადუმპსტა kela
1003: დუმპსტადუმპსტა tolmi
Jummi Tuumi!  (I hope this is finally correct!)

That looks perfect to me!

Excellent! I'm glad we finally got there.
It took a few tries, but we've now successfully counted from 997 to 1003 in Anti-Earth Finnish.
Thanks for your patience and for helping me construct the language!

Thanks, you just said "Excellent! I'm glad we finally got there.  It took a few tries, but we've now successfully counted from 997 to 1003 in Anti-Earth Finnish.  Thanks for your patience and for helping me construct the language!". Please say that again for me, but this time try to say it in AntiEarth. Remember not to use actual Finnish or English language!

Jummi Tuumi!  Kela tolmi neva viita.
Tolmi neva viita kuusko, kela neva viita seitsa, kela neva viita kahdeksu.
Harsi kela neva viita yhdeksu, tolmi neva viita tippsa.
Viita neva viita დუმპსტადუმპსტა.
Kuusko neva viita harsi, kuusko neva viita kela, kuusko neva viita tolmi.
Tolmi neva viita jummi tuumi AntiMaa keiliä!
Harsi kela neva viita jummi tuumi neva viita AntiMaa keiliä.

Jummi Tuumi!

---

How might a Finn on Earth hear that? Let's ask Google Translate.

Kela tolmi neva viita. ==> The coil is dusty and the Neva cape is dirty.

Tolmi neva viita kuusko, kela neva viita seitsa, kela neva viita kahdeksu. ==> Tolmi neva cape six, kela neva cape seven, kela neva cape eight.

Harsi kela neva viita yhdeksu, tolmi neva viita tippsa. ==> The net is a nine-pointed star, the dust is a tip.

Viita neva viita დუმპსტადუმპსტა. ==> Refer to neva Refer to думпстадумпста.

Kuusko neva viita harsi, kuusko neva viita kela, kuusko neva viita tolmi. ==> Spruce Neva cape resin, spruce Neva cape coil, spruce Neva cape dust.

Tolmi neva viita jummi tuumi AntiMaa keiliä! ==> Tolmi neva cape yummy AntiMaa keili!

Harsi kela neva viita jummi tuumi neva viita AntiMaa keiliä. ==> The resin coil is a new cloak, a new cloak, an Anti-Maa keili.