math and science education math stories


November 11, 2011 Challenges


These challenges are all based on dates written in the form xx/xx/xx or 11/11/11

What is the sum of the digits of the date 11/11/11?

What is the date this year (2011) whose digits add up to the smallest sum?

What other dates in 2011 (or over a chosen span of years) have digits that add to a sum that is less than or equal to 6?

Without using the digit 1, can you write an addition and a subtraction problem that has an answer of 11?

What is the next date that will have all identical digits? In how many years will it be?

What dates in 2011 (or over a chosen span of years) have digits without any skipping between the numbers?
(For example the date 2-22-11 had no skips between the numbers.)

If your clock shows that the time is 11:11 how much time will pass before your clock has all matching numbers again?

A football team has 11 players on the field at the same time. If the NFL has 32 teams, and they are all playing a game on a given Sunday, how many players have been on the field (let’s say that there are no substitutions)?

If you were born on this date (11/11/11) how many days would it be until a baby was born on a date that had all consecutive integers (2/2/22)? (this can be figured with leap years for an extra challenge!)

This is a great day to teach the 11 times trick- it’s explained in this 11 times video I made:


11 times tables
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