It was Emily's 10th birthday. She was 10 years old. She was so happy. "I'm so happy," she said. "I'm finally 10. Ten is two numbers. Ten is an adult number. Ten is a grown-up number. I'm an adult now. I'm a grown-up. I used to be nine. Nine is a kid number. Nine is for kids. I'm not a kid anymore." Her sister Irene said, "Of course you're still a kid. Teenagers are kids. You're not even a teenager yet. You're in fifth grde. Fifth grade is for kids. Twelfth grade is for kids, too. When you are 18, you will be in twelfth grade. You will still be a kid. You will be a kid for eight more years." Emily said, "No, you're a kid. You're only seven. Seven is a kid." Irene said she wasn't seven. She said she was seven and a half.