Technically, 68 should be hyphenated sixty-eight when used as a determiner (adjective) before a noun.
Nine hundred sixty-eight.
The number 76 is "seventy-six."
It is spelled "eight hundred sixty eight".
Eight hundred sixty-eight and eleven hundredths.
Sixty eight in French is spelled as "soixante-huit."
The currency amount $68 is "sixty-eight dollars."
The currency amount $68.00 is "sixty-eight dollars" (and no cents).
Three hundred sixty eight
Five hundred and sixty eight.
The number 268 is "two hundred sixty-eight." (As a year or address it may be spoke "two sixty-eight.")
The number 268 is "two hundred sixty-eight." (As a year or address it may be spoke "two sixty-eight.")
You spell it like: one hundred sixty-eight and thirty-sixhundredths.