Bedtime Math: Chain Reaction!!!

Hi everyone,

As promised, here’s a recent Bedtime Math Problem that lots of kids liked.   Like all of our riddles, there’s a quick intro at the beginning, followed by three fun math problems.   (And to make it extra-easy, we always list the answers at the end!)

Try it with your kids!   And if you find you want to try a few more, just visit our site at www.bedtimemath.org – we post a new problem every day!

Enjoy!

~ Laura

Dominos, the little rectangle tiles with the two sets of dots, are one of those totally simple objects that can turn into a ton of games.   Even if you aren't in the mood to match up dots, dominoes make the best building blocks ever.  Line them up carefully in curvy rows, and when you knock down the first tile it bumps the next one, which knocks down the next, and so on.  It triggers a long, rippling chain reaction, because when one goes down, it all comes down (kind of like life, actually).  If you check out this video, you'll see colored dominoes form the shapes of flags from around the world - see if you can spot your country's flag, and maybe you'll be inspired to build your own "domino effect."

Wee ones (counting on fingers): If you line up 6 dominoes to make a cool chain reaction, and they all fall except the very last one, how many dominoes fall?

Little kids: You line up 12 dominoes so they will knock each other down and make a lollipop roll off the table into your backpack. If you start the reaction and only half of the tiles fall, how many tiles remain standing?  Bonus: If you add 4 tiles to the end and try again, and they all fall successfully and knock off the lollipop, how many dominoes fall in total this time?

Big kids: You build a massive domino reaction on the floor, where a line of tiles branches into three new lines of tiles.  If there are 12 tiles in the start of the chain and 12 tiles in each of the three branches, how many tiles have you lined up in total?  Bonus: If at the end of each chain there's a cup holding 17 of your dog's favorite doggie treats, how many treats roll out for your dog if 2 of the 3 chains ripple all the way to the end?

 Answers:

Wee ones: 5 dominoes fall.

Little kids: 6 dominoes still standing.  Bonus: 16 dominoes.

Big kids: 48 tiles.  Bonus: 34 doggie treats.

And if you want to see dominoes set other objects into action,
check out this video, too!