Thirty days have September,
April, June, and November;
Thirty-one the others date,
Except in February, twenty-eight;
But in leap year we assign
February, twenty-nine.

So, what do we do with all of those 1/4 days? We add a day in a leap year! The extra day is added to the end of February. It becomes February 29. It’s called leap day!

Math Rules for Leap Years

Which years are leap years? Here are three simple rules for determining the leap years.

1. Every year divisible by 4 is a leap year
2. But every year divisible by 100 is NOT a leap year
3. Unless the year is also divisible by 400, then it is still a leap year.

Leap-Year Math Quiz

1. List the next five leap years after 2012:
2. Sara was born in 1988. What was the first leap year during her lifetime?
3. Circle the years that were leap years: 1900, 1972, 1956, 1946, 1992, 1886, 1420, 1600
4. List the next five century leap years:
5. The day of the week that a date falls on usually skips forward one day the following year. January 1, 2011, was a Saturday; January 1, 2012, was a Sunday. But if there’s a February 29 between the two dates, the day of the week “leaps” forward an extra day: January 1, 2013, will be on a Tuesday (instead of Monday). On which day will January 1 fall in…
   • a. 2014?
   • b. 2017?

BONUS: A leap year occurs every four years. Based on that information, about how many hours longer than 365 days do you think it takes Earth to revolve around the sun?