Tag Archives: puzzles

So….When IS Cheryl’s Birthday???


I absolutely LOVE seeing a Singapore Math problem in the news! This challenging word problem taken from a recent Singapore and Asian School Math Olympiad (SASMO) contest has stumped people worldwide, and continues to go “viral” across the Internet. In case you haven’t yet seen it, the problem looks like this:

cheryl birthday

Now that you’ve probably read the problem several times over, how is it possible that a math problem contains no numbers other than the dates? The answer to that question is actually much more simple than the solution itself. Math doesn’t have to be limited to problems involving natural numbers or integers.

  • Math is about logic and reasoning.
  • Math is about creating order and patterns.
  • Math is about making sense of something that initially appears senseless.

Tackling problems like this can help children of all ages build number sense – a skill critical to mathematical achievement and success. But even more important, problems like this help to create the thought process required for rationalizing and finding solutions for problems that span subject areas and curricula. The satisfaction gained from attempting and ultimately solving these types of puzzles creates an attitude where “I don’t get it” is replaced with “let’s try another one!

So when IS Cheryl’s birthday? If you haven’t figured it out yet, watch the video below, courtesy of the BBC. And if you’re still not sure of how they came up with the answer, ask your kids. Chances are great that their exposure to Singapore Math strategies can make solving this problem easier than blowing out the candles on Cheryl’s birthday cake.