The post Chickens Playing the Xylophone appeared first on Bedtime Math.

]]>The xylophone is such a fun way to make music. You hit bars of different lengths with a stick, and they ring to play notes. Turns out even chickens can do this. A Colorado farmer named Kris Garrett worried that her chickens were bored, spending all day just pecking at corn and at each other. So she stuck a xylophone on the wall in their yard to see what would happen. The chickens started pecking at the xylophone with their beaks, and found out that this sounded really great! As you can hear in this video, they play a pretty good song…if you listen carefully, it starts off sounding like “Mary Had a Little Lamb.” Of course, they call it “Kris Had a Jazzy Chick.”

*Wee ones:* How many colored bars does the xylophone have? Check out the picture!

*Little kids:* Which color bar is 2 to the left of the green one? *Bonus:* There are 11 chickens, but only 8 bars. If each chicken gets 1 bar to play, how many chickens have to wait their turn?

*Big kids:* If each of the 11 chickens pecks the xylophone twice, how many notes do they play? *Bonus:* If a song has 8 lines with 6 notes for each, and the chickens take turns in order playing them, how many chickens will get to play 1 more note than the rest?

__Answers:__

*Wee ones:* 8 bars.

*Little kids:* Orange. *Bonus:* 3 chickens.

*Big kids:* 22 notes. *Bonus:* 4 chickens. They need to play 48 notes, so after each plays 4 notes, they will have played 44 so far, leaving 4 more.

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]]>The post Are There More Boys or Girls? appeared first on Bedtime Math.

]]>Our fan Aliza W. just asked us a great question: are there more girls or boys in the world? It seems like it should be about even, right? But the math gets more exciting than that. At birth, more boys are born: for every 100 baby girls, there are 106 baby boys. If you look at people of all ages, though, it evens out to about 1 boy for every girl. That’s partly because women live longer than men. In fact, if you look only at people 65 years or older, there are only 3/4 as many men as women. Remember, though, that for any age the boys are *bigger* than the girls. So if the whole world did a giant tug of war, the boys would have a good chance at winning.

*Wee ones:* Do you have more girls than boys in your family, or more boys than girls? How many of each?

*Little kids:* If a boy swings on the monkey bars, then a girl, then a boy…does a girl or a boy go 6th? *Bonus:* If there are 7 kids on the jungle gym and there’s 1 more boy than girl, how many of each are there?

*Big kids:* If 106 boys and 100 girls line up for tug-of-war, how many kids would that be in total? *Bonus:* If 19 more boys show up, how many more girls do we need to have equal numbers of each?

*The sky’s the limit:* If 800 200-pound men do tug of war against 1,000 women, how much do the women have to weigh to match the men’s total weight?

__Answers:__

*Wee ones:* Different for everyone…count up your family!

*Little kids:* A girl goes 6^{th}. *Bonus:* 4 boys, 3 girls.

*Big kids:* 206 kids. *Bonus:* 25 girls.

*The sky’s the limit:* 160 pounds each, since the men weigh 160,000 total.

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]]>The post Land of the Flying Pumpkins appeared first on Bedtime Math.

]]>With Halloween and Thanksgiving behind us, America is done with pumpkins. So now what do we do with the leftover ones? We throw them. As our friend Mike F. just shared, every year there are “Punkin Chunkin” contests across the U.S., where people bring all kinds of crazy machines they build to hurl pumpkins. The farther you chuck your pumpkin, the closer you are to being a winner. This video shows a “trebuchet”: A giant heavy weight hangs from one end of a long arm, with the pumpkin at the other end. The weight falls, spinning the arm at top speed. The pumpkin flies off, and in this case it flew 2,402 feet! We’re pretty sure no one wanted to eat that pumpkin after that.

*Wee ones:* Find 3 things in your room that you can pick up. Which one feels the heaviest?

*Little kids:* If the machine takes 2 seconds to drop the weight and 2 seconds to spin the arm, how long does it take to fling the pumpkin? *Bonus:* If you start setting up your machine at 8:00 am and it takes 3 hours, at what time are you ready to chuck pumpkins?

*Big kids:* If all the pumpkins you chuck crack open except every 3^{rd} one starting with the 3^{rd}, does the 19^{th} pumpkin crack open? *Bonus:* If your one friend’s pumpkin flies 800 feet, and another friend’s pumpkin flies 1,400 feet, how far does your fly if its distance is halfway between those?

*The sky’s the limit — even for pumpkins:* A mile has 5,280 feet. Did the record-breaking pumpkin fly a half mile with its 2,402-foot flight?

__Answers:__

*Wee ones:* Items may include toys, shoes, books, or a chair or small table.

*Little kids:* 4 seconds. *Bonus:* At 11:00 am.

*Big kids:* Yes. The 18^{th} does not. *Bonus:* 1,100 feet. The other two are 600 feet apart, so your flight is 300 feet different from each.

*The sky’s the limit:* Not quite. If you doubled its flight, you’d get 4,804 feet, which is less than a mile.

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]]>The post When Platypuses Glow Crazy appeared first on Bedtime Math.

]]>Other than people, the platypus might be the weirdest animal on Earth. When this creature was first found, it was hard to believe one animal had this strange mix of body parts. It is a furry mammal, but has duck-like feet, and is one of only two mammals that lay eggs. And now to top it off, we’ve learned that platypuses glow in the dark! The platypus’ fur has “fluorescence,” which means if you shine one color light on it, it gives off a different color glow. Under black light, a platypus glows blue-green, as the picture shows. And why does it glow? Scientists don’t know, and we bet the platypuses don’t either.

*Wee ones: *The platypus usually lays 2 eggs, while another animal, the emperor penguin, lays 1 egg. Which animal lays more?

*Little kids: *Flying squirrels also fluoresce – bright pink! If you spy 8 pink flying squirrels in a tree but then 3 fly off, how many are still in the tree? *Bonus: *If flying squirrels act as flashlights for ground squirrels, and each flying squirrel can lead 5 ground squirrels, how many flying squirrel flashlights do 10 ground squirrels need?

*Big kids: *Platypuses dig super-long tunnels called burrows. If a 2-foot long platypus makes a burrow that’s 30 times as long as she is, how long is that burrow? *Bonus:* How many 1 1/2-foot platypuses could line up end to end in that tunnel?

__Answers:__

*Wee ones: *The platypus lays more, because 2 is more than 1.

*Little kids: *5 squirrels are still in the tree. *Bonus: *2 flying squirrel flashlights for 10 ground squirrels, because 10 / 5 = 2.

*Big kids: *60 feet long. *Bonus:* 40 platypuses that length. You’re dividing 60 feet by 1 1/2 feet. 1 1/2 = 3/2, and 60 / 3/2 = 60 x 2/3 = 40.

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]]>The post The Race to Eat 100 Plates appeared first on Bedtime Math.

]]>Thanksgiving might be behind us, but the holiday eating season is just getting started! Maybe that’s why our friend Charlize C. asked, how long would it take to eat 100 plates of food? Well, that depends on both the food and the person eating it. 100 plates of lettuce will feel light and fluffy compared to 100 plates of fried chicken. But competitive eaters can handle it. These are crazy people who can eat 74 hot dogs in 10 minutes, or 13 grilled cheese sandwiches in just 1 minute. *IF* you could eat nonstop at that pace, that speed-eater could eat 100 plates of grilled cheese in fewer than 8 minutes! After all the turkey and stuffing, maybe we’ll stick with salad.

*Wee ones: *If you ate 2 plates of food on Thanksgiving and 1 plate of leftovers the next day, how many plates of Thanksgiving food did you have?

*Little kids:* If you eat a plate of pancakes, then a plate of pasta, then a plate of pancakes, then a plate of pasta…which food is on the 9th plate? *Bonus:* If you eat 10 plates of pancakes every day for 1 week, can you eat 100 plates of pancakes in those 7 days?

*Big kids:* If you can eat 12 burgers in 3 minutes and 2 pizzas in 1 minute, which do you eat faster, a burger or a pizza? *Bonus:* How many more burgers than pizzas can you eat in 15 minutes? * *

*The sky’s the limit:* If a speed-eater eats twice as many hamburgers as pizzas, and twice as many salads as hamburgers, and eats 49 plates in total…how many plates of each food does she eat?

Answers:

*Wee ones: *3 plates of Thanksgiving food.

*Little kids:* Pancakes, since it’s on the 1st, 3rd, and every following odd-numbered plate. *Bonus: *Not quite – you’ll eat only 70 plates. * *

*Big kids: *You eat burgers more quickly: dividing 12 burgers by 3 minutes comes to 4 burgers per minute, compared to 2 pizzas in a minute. *Bonus:* 30 more burgers than pizzas. 4 burgers per minute comes to 60 burgers, while 2 pizzas per minute comes to “only” 30 pizzas.

*The sky’s the limit:* 7 plates of pizza, 14 plates of hamburgers, and 28 plates of salad. Each pizza comes with 2 burgers and 4 salads (2 salads per burger), which makes a set of 7 plates, and there are 7 sets of 7 plates in 49 plates. That gives us 7 pizzas, then twice as many burgers and so on.

You can see this in action if you solve this using algebra. Since the pizza (p), hamburger (h) and salad (s) plates add up to 49, then:

p + h + s = 49

And since there are twice as many hamburger as pizza plates: h = 2p

And twice as many salad plates as hamburger plates: s = 2h = 4p

Substituting those values back into the original formula:

p + h + s = p + 2p + 4p = 49

7p = 49

P = 7 = the number of pizzas. From there you use 2p and 4p to figure out the other foods!

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]]>The post A New Job for Your “Chopper” appeared first on Bedtime Math.

]]>You can do a lot with a drone (a mini-helicopter). But how about cooking Thanksgiving dinner with one? And we don’t mean carrying dinner with it: we mean using that chopper to *chop* dinner. In this crazy video shared by our friend Michael B., somebody uses those whirling blades to peel potatoes, then peel and chop carrots. Then the drone hauls the turkey outside and lowers it into boiling oil, hovering for 25 minutes while the bird cooks. Finally the cook sticks egg beaters onto the drone, and uses it to whip potatoes, heavy cream, pumpkin pie mix and gravy all at once. It makes a huge mess, but dinner is served!

*Wee ones:* How many bowls can you see under the drone?

*Little kids:* If the drone finishes mixing the top left bowl, then the bottom right bowl, then the bottom left bowl, which bowl is last to finish? *Bonus:* If it peels 5 potatoes and 1 more carrot than that, how many veggies does it peel in total?

*Big kids:* If the turkey (or quail?) starts cooking at 12:45 pm and takes 25 minutes, when does it finish? *Bonus:* If each cook with a drone can make dinner for 8 people, how many drones and cooks are needed to make enough dinner for 30?

__Answers:__

*Wee ones:* 4 bowls.

*Little kids:* The top right bowl. *Bonus:* 11 veggies, since it peeled 5 potatoes and 6 carrots.

*Big kids:* At 1:10 pm. *Bonus:* 4 cooks and 4 drones, since 3 of each can make dinner for only 24 people total.

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]]>The post Watch Out for the Flying Guitars appeared first on Bedtime Math.

]]>You can make art out of just about anything. Sculptures made of clay, castles made of sand, bridges made of pretzel sticks and marshmallows. Well, as we see here at the Washington Convention Center, you can even use musical instruments and furniture. That circle at the top is made of 30 guitars. The blue ring has kayaks, a skinny type of boat, while the statues below have rings of bicycles and bar stools. Any time you repeat a shape to make a pattern, you’re making art using math. Just make sure you stick it really well to the ceiling.

*Wee ones:* How many kayaks does that blue sculpture have?

*Little kids:* If you made your own triangle sculpture of 3 bicycles, how many wheels would they have? *Bonus:* If at each corner you added a unicycle (which has just 1-wheel), now how many wheels do you have?

*Big kids:* If you strum the 1st of those 30 guitars, then every 4th guitar after that, will you strum that 1st guitar when you go around once? *Bonus:* Those are all 4-legged stools in that 26-stool statue. How many legs do they have in total?

__Answers:__

*Wee ones:* 5 kayaks.

*Little kids:* 6 wheels. *Bonus:* 9 wheels, since you’ve added a wheel at each of 3 corners.

*Big kids:* Not quite – you’ll strum the 29th, then jump to the 3rd. *Bonus:* 104 stool legs.

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]]>The post A-Mazing Pets appeared first on Bedtime Math.

]]>This here is a classic maze: walls that run front to back and side to side, with gaps to pass through. You might have drawn through one on paper, but here the Bedtime Math guinea pigs get to solve a real one. Rats and mice can solve a maze to find the cheese, too. This webpage tells pet owners how to train a mouse to run a maze. You start by leaving a trail of treats from the start all the way through to the finish. Each day you space the treats farther and farther apart, until finally there’s just one treat at the end. Luckily we humans just get to eat our snacks off a plate.

*Wee ones:* Where is Snickers, the black/white/caramel guinea pig: on your left, or on your right?

*Little kids:* If Hershey (the brown guinea pig) takes 6 minutes to solve the maze, and Snickers (the black/white/caramel one) takes 1 minute longer, how long does Snickers take? *Bonus:* If they start learning the maze on a Monday, and finally learn it 4 days later, on what day do they solve the maze?

*Big kids:* If each row of the maze is 6 inches wide, and there are 6 rows going across, how wide is the maze? *Bonus:* How wide is it in feet and inches? (Reminder if needed: A foot has 12 inches.)

*The sky’s the limit:* If Hershey speeds up and takes 30 seconds to solve it, while Snickers takes 72 seconds, and their rat friend’s time is twice as far from Snicker’s time as Hershey’s, how fast does the rat solve it?

__Answers:__

*Wee ones:* On your right.

*Little kids:* 7 minutes. *Bonus:* On Friday.

*Big kids:* 36 inches. *Bonus:* Exactly 3 feet.

*The sky’s the limit:* 44 seconds. Hershey and Snickers are 42 seconds apart, and if the rat’s time gap from Snickers is double the gap from Hershey, we need to divide that 42 into 3 parts. 1/3 of 42 is 14, so the rat is 14 seconds from Hershey, and 28 seconds from Snickers. By the way, the rat’s time has to be less than Snickers…there’s no time longer than Snickers’ that can be twice as far from Snickers as from Hershey, because the gap from Hershey would always be bigger.

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]]>The post Fibonacci Day! appeared first on Bedtime Math.

]]>One of the most fun things about numbers is the patterns they make. You can say, “OK, my pattern is 1, 4, 7, 10…” and then your friend can guess the next number is 13 because you keep adding 3. Or you can say “1, 3, 9, 27…” what’s next? One of the most interesting patterns out there is the Fibonacci series: you start with 0,1, and each number is always the last two numbers added together, So 0+1 gives us 1, and then 1+1 is 2. Then you add 1+2 to get 3. Then 2+3 makes 5. Then you get 8, 13, 21, 34…and so on. That’s why today is Fibonacci Day, because the date is 11/23 (1-1-2-3). We celebrate Fibonacci numbers because lots of objects in nature grow in shapes driven by them. Snail shells spiral around these numbers, as you see in this picture, and the seeds in the middle of a sunflower, and even the hair on your head! As we’ll see, today isn’t the only good day to celebrate these cool numbers.

*Wee ones:* Can you remember the set of numbers 1, 1, 2, 3, 5, 8? See if you can say it back!

*Little kids:* Which is bigger, the jump from 3 to 5, or the jump from 5 to 8? *Bonus:* What’s the next number in this pattern: 1, 3, 5, 7, 9…?

*Big kids:* What’s the next Fibonacci number after 34? *Bonus:* For any Fibonacci number from 3 onward, which is bigger, 2 times that number, or the next Fibonacci number?

*The sky’s the limit:* If we look at just the single-digit Fibonacci numbers, how many dates this year had some set of consecutive Fibonacci numbers in the right order? (Just look at month and day, and in that order.)

Answers:

*Wee ones:* Try to repeat 1, 1, 2, 3, 5, 8!

*Little kids:* The jump from 5 to 8. The jumps keep getting bigger. *Bonus:* 11, because you’re adding 2.

*Big kids:* 55. *Bonus:* Doubling a Fibonacci number will always give you a bigger number than the next Fibonacci number. Since each number is added to the one before it to make the next one, and since the one before it is always smaller, your new number can’t be fully double the most recent number. 5 has to get added to 3 to make 8, so that’s less than 2×5 (10). And 8 has to get added to 5 to make 13, which is less than 16. As the numbers get really big, each number is about 1.6 times the previous number.

*The sky’s the limit:* 10 dates: 1/1, 1/2, 1/12, 1/23, 2/3, 3/5, 5/8, 11/2, 11/23, and 12/3. By the way, in the year 2058 we’ll get to have the awesome date 11/23/58!

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]]>The post Play with Your Food appeared first on Bedtime Math.

]]>Sure, grown-ups tell us not to play with our food. But if you’re making art out of it, is it so bad? There are all kinds of shapes we can cut. Slice brownies into triangles and squares to make a house or a rocketship. Cut a pancake into squares, then eat every other bite to make a checkerboard. If you cut 4 or 5 long grooves out of a carrot, when you slice the carrot you’ll get little flower shapes, like in the picture on the left. The question is, can this make even your least favorite food taste good?

*Wee ones:* How many petals does each carrot flower have?

*Little kids:* If you cut a baby carrot into 5 little flowers, and the 4 long, skinny carved-out sticks are “grass,” how many carrot pieces do you have? *Bonus:* If you have 9 carrot flowers and eat every other one starting with the 1st, how many do you get to eat?

*Big kids:* If you cut a pancake into 6 rows and 6 columns, how many checkerboard bites do you have? *Bonus:* If you eat 3 checkerboard squares from each row, how many do you have left?

__Answers:__

*Wee ones:* 5 petals.

*Little kids:* 9 carrot pieces. *Bonus:* 5 carrot flowers.

*Big kids:* 36 squares. *Bonus:* 18 squares, since you eat half of the total (3 out of every 6).

The post Play with Your Food appeared first on Bedtime Math.

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