You say: watashiwa juusai desu.
'Ten days' is 十日 (tooka) in Japanese.
玩具店 Omocha-ten
"Jyu-Roku" Literally Ten Six
Go-Jyu-Go Literally five-ten-five
tentou, tokoyonokuni, oozora, hebun, joukai, ten 天国
ku ji to juji no aida ni
蝶の天使 /chou no ten shi/.
Yes and no. It is the same up to 10,000. Then it changes. For 100,000, we say one hundred thousands. They say ten ten-thousands. So it gets a little complicated.
天国の太陽 /ten go ku no tai you/ is a way to say 'heaven's sun' in Japanese.
鮭 - sake (same pronunciation as the drink, and in both words the 'e' has a soft vowel sound as in the word 'ten'.
"ten-goku" is heaven/paradise and has the same contextual meaning.
The phrase 'ten tails' would be 十本のしっぽ (juppon no shippo) in Japanese. However, the word十尾 (juubi) has been used in the anime 'Naruto' to refer to a demon called 'Ten Tails'. I wouldn't recommend using this word, as it could also mean 'ten small fish'.