1. The difference between shoe sizes 230 and 240 is significant, amounting to 1 centimeter. 2. A shoe size 230 indicates a inner length of 23 centimeters, whereas a size 240 corresponds to an inner length of 24 centimeters. 3. Consequently, there is a clear distinction of 1 centimeter between shoe sizes 230 and 240. 4. Shoe sizes are a standard unit used to measure the foot for proper shoe fitting. 5. Different countries employ various shoe size systems, typically based on both foot length and width. 6. Foot length refers to the length of the foot of the wearer or the length of the shoe last used by the manufacturer. 7. The imperial system of shoe sizing is used in countries such as the United Kingdom, Ireland, Pakistan, India, and South Africa. 8. In this system, adult shoe sizes are based on the foot length corresponding to the maximum length in the old British foot measurement, which is 30.48 centimeters. 9. Adult shoe sizes start at 24, which corresponds to 8 inches,定義為1號鞋. 10. Therefore, a length of 23 inches is designated as the zero shoe size in this system.