Step 1: A normal year is a leap year if it is divisible by 4 (for example 2024). Step 2: A century year (ending in 00) is a leap year only if it is divisible by 400. Step 3: 1900, 2100 and 2200 are century years not divisible by 400, so they are not leap years. Step 4: 2000 ÷ 400 = 5, so 2000 is divisible by 400 and is a leap year. Answer: 2000.