Matthew 14:21 – ανδρες ωσει πεντακισχιλιοι (“men about five thousand”)
Mark 6:44 – πεντακισχιλιοι ανδρες (“five thousand men”)
Luke 9:14 – ωσει ανδρες πεντακισχιλιοι (“about men five thousand”)

Matthew 15:38 – τετρακισχιλιοι ανδρες (“four thousand men”)
Mark 8:9 – τετρακισχιλιοι (“four thousand”)

So ανδρες (“men”) is present in all of the verses except Mark 8:9, where just the number is given.

The key question is whether Mark 8:9′s “4000″ implies “4000 men”, “4000 people”, or is ambiguous.

All three positions are represented in mainstream translations: The NIV goes for “men”, the NRSV goes for “people”, and the NASB and ESV go for ambiguity.

I think that preserving the ambiguity is best here, and this should be seen as a possible inconsistency, but certainly not as a flat-out contradiction.

The Greek in Mark’s account says that those that ate were 4000.

It does not say 4000 people. It is possible that Mark intended 4000 men (and wasn’t counting the women and children). The case is Nominative, Masculine, Plural. This, of course, does not guarantee that Mark meant to be referring only to the men. I think that it is typical in ancient languages to use the masculine to refer to mixed gender groups even if the women vastly outnumber the men.

But what he and the other Gospel writers say in the other cases suggests that here:

1. Mark intended 4000 men, when he simply said 4000.
2. Mark was not counting the women and children (as usual).
3. Mark did not mention that he was not counting them.
4. The mix of the crowd was not much different than the mix of any other crowd that gathered around Jesus. We need not assume that it was predominately male.