Seven ninths minus four ninths is 1/3.
One whole is nine ninths. Nine ninths minus four ninths equals five ninths.
Two thirds is six ninths; six ninths minus four ninths is two ninths.
Five and four-ninths
Firstly, do 11 minus 4 = 7. So, now we have 7 and two ninths, minus five ninths. Much easier, 6 and 6 ninths.
Two thirds minus two ninths is 4 ninths. Two thirds is 6 ninths. 6 ninths minus 2 ninths is 4 ninths.
Expressed as a proper fraction in its simplest form, 4/9 - 2/3 = -2/9 or minus two ninths.
1/9 (one ninth)