In a span of 100 years, there are typically 24 or 25 leap years.

Explanation:

• A leap year occurs every 4 years.
• However, years divisible by 100 are not leap years unless they are also divisible by 400.

Calculation:

• Every 4 years: 100 ÷ 4 = 25 leap years
• But years divisible by 100 are not leap years unless divisible by 400.
• In 100 years, there is usually 1 such century year (e.g., 1900).
• If that century year is not divisible by 400 (like 1900), it is not a leap year, so subtract 1.
• So, 25 - 1 = 24 leap years in 100 years (e.g., from 1901 to 2000).

If the 100-year period includes a year divisible by 400 (like 2000), then that year is a leap year, so there would be 25 leap years.

Summary:

Scenario| Leap Years in 100 Years
---|---
Century year not divisible by 400 (e.g., 1900)| 24
Century year divisible by 400 (e.g., 2000)| 25

Let me know if you'd like me to explain the leap year rules in more detail!