Como Ender já estava 10 enquanto estava no lago?

Ender foi promovido a comandante do Dragon Army, quando tinha nove anos e meio.

"Content. He's doing well. His mind is keen, his play is excellent. Young as he is. we've never had a boy better prepared for command. Usually they go at eleven. but at nine and a half he's top flight."

Ele esteve com o Dragon Army por dois meses:

There was no guarantee that they'd give him the usual three months to get his army together before sending them into battle.

---

"We've still got a month to go before our training period is normally supposed to end. About time we started doing formations.

E então ele esteve na Terra por 3 meses.

So that's why you brought me here, thought Ender. With all your hurry, that's why you took three months, to make me love Earth.

Isso faria ele ter 9 anos de idade, indo para o 10 quando ele conhece Valentine. Então, por que Valentine diz que Ender tinha 10 anos?

She got in the car. "Ender's only ten years old," she said. "I thought you told us the first time he'd be eligible for a leave was when he was twelve."

Ela esqueceu quantos anos ele tinha? (Não é provável que ela comemoraria seu aniversário todos os anos com seus pequenos incêndios.)

E mais tarde, enquanto na jornada de rebocadores para Eros:

Five years. Only five years until the fleet arrives, and I don't know anything yet, "I'll only be fifteen in five years," Ender said.

"Going on sixteen," said Graff. "It all depends on what you know."

Mas o rebocador levou um total de apenas 3 meses,

"Oh, no, of course not. I.E. Command is on the minor planet Eros, which should be about three months away from here at the highest possible speed. Which is the speed you'll use, of course."

Assim, mesmo que a conversa tenha ocorrido no final do Journey Ender, seria apenas um mês ou dois com mais de dez anos de idade. Por que Graff diz que ele estaria "com dezesseis" em cinco anos?