I skipped over zero as we counted, but she confidently picked up the number and declared it an oval.
当我们数数时，我跳过了零，但我女儿很自信地说出了零，并且说零是一个椭圆。
Any time we make a corner case into an error we need to carefully specify exactly what the error case is so that we can implement it correctly and test it confidently.
