I got 100 on my math test, pretty impressive don't you think?
This is 100% natural energy, pretty amazing, wouldn't you say?
この場合、impressive や amazing などを使って次のような言い方ができますよ。
ーI got 100 on my math test, pretty impressive don't you think?
「数学のテストで100点だよ、すごくない?」
ーThis is 100% natural energy, pretty amazing, wouldn't you say?
「これは自然エネルギー100%だよ、すごくない?」
ご参考まで!