The post “Canstruction” appeared first on Bedtime Math.

]]>It’s awesome when people get together to build something really cool-looking — and even better when it helps other people. As our friend Suzanne D. shared with us, at Canstruction people around the country build giant statues out of cans of food. These Despicable Me guys are made of cans of tuna fish; people also makes statues of lizards, birds, castles, and designs like giant spirals. The cans still have food in them, by the way, so these statues are heavy to build and hard to balance. Builders win prizes like Best Meal (the statue with the yummiest mix of foods) and Best Use of Labels (great colors and patterns). Then the cans are given to other folks who don’t have enough food. Maybe Despicable Me is a good guy after all.

*Wee ones:* How many eyes can you count on the Despicable Me guys in the photo?

*Little kids:* If you stick on a red can, then a blue can then a red, then a blue…what color is the 7th can? *Bonus:* If the front guy’s arms each have 10 cans, how many cans make up his arms?

*Big kids:* Each Despicable Me guy has what looks like 41 rows of cans top to bottom. If tuna cans are 2 inches tall, how tall are the statues? *Bonus:* What does that equal in feet and inches — and how much taller than you are they? (Reminder: A foot has 12 inches.)

*The sky’s the limit:* How many cans did it take to build each of these statues? Do some guessing and some math, and see what you come up with! (You “can” assume the statue is hollow — just cans around the outside surfaces.)

Answers:

*Wee ones:* 3 eyes.

*Little kids:* Red. *Bonus:* 20 cans.

*Big kids:* 82 inches. *Bonus:* 6 feet 10 inches – and for how much taller, different for everyone.

*The sky’s the limit:* We got about 750…here’s what we did. We counted about 23 equal layers in the head and shoulders/chest, and 11 cans in the half of the layer we can see, making 22 cans per layer. That comes to 506 cans. For the pants, we assumed each layer has 2 fewer cans than the layer above it. For the 8 layers in the pants, that means adding 20+18+16+14+12+10+8+6. To add that quickly, that’s the same as 20+6, then 18+8, and so on, which is four 26s or 104 more cans. For the head, similar thing: 6 layers would give 20+18+16+14+12+10, which is the same as six 15s, or 90. That gives us 506+104+90, which comes to exactly 700. Then there are 36 in the arms (we count 18 in each) and 12 in the feet (6 in each), bringing us to 748 tuna cans in each statue.

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]]>The post Checkerboard Chocolate appeared first on Bedtime Math.

]]>When we saw the photo of these amazing chocolates, the first thing we asked was, “Would anyone *want* to eat them?” How can you mess up something that looks so cool? These perfectly shaped mathematical wonders were made by Japanese company Nendo for the big Maison & Objet design show in Paris (that’s French for “House and Object”). The candies were made by pouring chocolate into a “mold,” a hollow shape cut so that when the candies cool down, they pop out looking like these. Suddenly a flat chocolate bar doesn’t seem as exciting as a spiky crown or checkerboard chunk — but in any shape, it all tastes good.

*Wee ones:* How many chocolates can you count in the picture on the left?

*Little kids:* How many mini-cubes can you count on the top side of the checkerboard chocolate in the middle of the photo? *Bonus:* How many edges do you think the cube in the bottom left corner has?

*Big kids:* How many mini-cubes of chocolate do you think the checkerboard candy has, if the very center cube is empty? *Bonus:* How many mini-cubes would it have if all empty cube spaces were then filled with milk chocolate?

__Answers:__

*Wee ones:* 9 chocolates.

*Little kids:* 5 cubes. *Bonus:* 12 edges, like any rectangular “prism” or box.

*Big kids:* 14: it has 5 in the top layer, 4 below, then 5 on the bottom. *Bonus:* 27, since it’s a 3x3x3 cube!

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]]>The post Pillow Fight for Pets appeared first on Bedtime Math.

]]>How would you feel if you went to bed at night ready to sleep, and found someone already sleeping in your spot? You’d be pretty ticked off, right? Well, that’s what happens to a small dog in this video, when the cat of the house tries to take over the doggie bed. The French bulldog is not happy at all, and tries to scare off the cat, who just sits there and doesn’t seem to care. Cats weigh around 8 to 12 pounds, while French bulldogs don’t weigh that much more, about 20-28 pounds. Sure, ants can move objects that are 50 times their own body weight, but this pup can’t do that. He may lose this pillow fight.

*Wee ones:* If the pup drags the doggie bed (and cat) 6 feet down the room, takes a breath, and then drags it 1 foot more, how many feet did he drag it?

*Little kids:* How many paws do these 2 pillow-fighters have in total? *Bonus:* If the dog is 5 years old and moved there when he was 2, and the cat is 9 years old and moved there when he was 4, how long have they lived there together?

*Big kids:* If the cat pulls this stunt every 3rd day starting on a Sunday, how many times does he do it till it’s on a Sunday again? *Bonus:* If the dog weighs 20 pounds and could move 50 times his own weight, how heavy a cat could he shove?

Answers:

*Wee ones:* 7 feet.

*Little kids:* 8 paws. *Bonus:* For 3 years, once the dog got there; the cat has been there 5 years.

*Big kids:* 7 more times: since the week isn’t divisible by 3, he has to cycle through 21 days. *Bonus:* 1,000 pounds!

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]]>The post Your Own Tie-Dyed Crayons appeared first on Bedtime Math.

]]>We all know some crayon colors are more popular than others. The blue and red get used over and over, while the burnt sienna might not have much work to do. But what can you do with all the leftover little pieces? You can melt them down and make *new* crayons. As this page on instructables.com shows, crayons melt at just 275 degrees. So if you toss the stubs in a mini-muffin tin and bake them, they’ll melt and mix, giving you swirly, tie-dyed crayon chunks. The edges are sharp enough to draw thin lines, and if you want to switch to a different color, just flip the muffin over in your hand!

*Wee ones:* If you have red, orange, yellow, green and blue crayons, how many colors do you have?

*Little kids:* What colors do you see in the tie-dye crayon in the bottom right corner? Point to it! *Bonus:* If you use 3 new colors in each tin, how many colors will 3 muffin crayons use?

*Big kids:* The crayon muffins take up to 13 minutes to bake. If you start at 3:45 pm and bake them for 13 minutes, when do they finish? *Bonus:* If you need 8 pieces in each muffin cup, what’s the greatest number of complete crayon muffins you can make with 50 pieces?

*The sky’s the limit:* If you have blue, red, and purple crayon pieces, and in your 24-muffin tin you put blue in 1/2 of the cups, red in 1/3 of them, and purple in 1/4 of them, what’s the smallest number of crayon muffins that have to hold at least 2 different colors?

__Answers:__

*Wee ones:* 5 colors.

*Little kids:* Mostly red, with 2 shades of green. *Bonus:* 9 colors.

*Big kids:* At 3:58 pm. *Bonus:* 6 crayon muffins: they will use 48 pieces, leaving 2 leftovers.

*The sky’s the limit:* 2 crayon muffins. The blue will go into 12 of the cups, and red can go into 8 of the other 12 cups. That leaves just 4 empty cups, but purple has to fill 6 cups, so there will be 2 that have to pair purple with either red or blue.

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]]>The post Swimming with Killer Whales appeared first on Bedtime Math.

]]>Imagine floating on the ocean and having a giant killer whale swim right under you! That’s what happened to Rich German in California. He was floating around on a paddleboard, and five orcas suddenly swam up to him. A paddleboard is small and flat — it doesn’t have sides like a boat. So there was nothing between him and them. Orcas are the big, beautiful black-and-white cousins of the dolphin: males can be up to 30 feet long and weigh up to 6 tons. That fin on top can be 6 feet tall! Even though they’re nicknamed “killer whales,” luckily Rich knew that they’re gentle animals, so he wasn’t scared. To see what he saw, check out this video (the orcas show up about 2 minutes in).

*Wee ones:* 5 orcas swam up to Rich. What numbers would he say to count them up?

*Little kids:* If you’re 4 feet tall and the orca’s fin is 6 feet tall, how many feet above you does it reach? *Bonus:* If your bedroom is about 10 feet long, how many rooms that size would you have to line up to match a 30-foot orca?

*Big kids:* An orca weighs about the same as a school bus. If your bus weighs 10,000 pounds and the orca weighs 1/5 more than that, how heavy is the orca? *Bonus:* If you and your friends each weigh 50 pounds, and an orca can carry 200 pounds, how many of you can ride that orca at once?

__Answers:__

*Wee ones:* 1, 2, 3, 4, 5.

*Little kids:* 2 feet more. *Bonus:* 3 bedrooms — that’s how huge they are!

*Big kids:* 12,000 pounds, since it weighs 2,000 pounds more. *Bonus:* 4 of you.

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]]>The post Krush of K’Nex appeared first on Bedtime Math.

]]>We are loving this video of the world-record K’Nex ball roller coaster, and you probably will, too. K’Nex are those cool, colorful snap-together sticks. As with Lego or Tinkertoys, you can add on more and more pieces to make giant shapes and structures. This one, built by Austin Granger, uses more than 126,000 pieces! Balls travel up little elevators, roll down wavy ramps, and ride ferris wheels, all of which together fill a huge warehouse. Blinking lights line some of the paths to add pizzazz. There’s even one of those toilet-bowl drains where the balls circle around and around before going down the hole. See if you can follow all those balls, and guess how many sticks each one actually touches!

*Wee ones:* The ball “elevators” run up and down a straight line. See if you can spot any straight up-and-down lines in your room.

*Little kids:* If you snap on a blue K-Nex, then a red, then a white, then a blue to start the pattern again, what color is the 6^{th} stick? *Bonus:* How many sticks do you snap together to make a cube? If needed, look at a rectangular box-shaped object to see the edges!

*Big kids:* If the ball takes 14 seconds to roll to the left on a ramp, then just 1/2 that time to roll back to the right, how long does that whole back-and-forth take? *Bonus:* If a new ball starts at that first spiral every 10 seconds, how many balls will start the trip during a 5-minute stretch — including the very first at 0 seconds?

*The sky’s the limit:* If the 126,000-piece ramp uses equal numbers of red, blue, green, white, and black sticks, but 4 times as many yellow sticks as red, how many sticks of each color does it use?

__Answers:__

*Wee ones:* Answers might include the vertical (up and down) edges of windows, doors, dressers and other furniture, and stripes in curtains.

*Little kids:* A white stick. *Bonus:* 12 sticks: 4 on the bottom, 4 up-and-down side, and 4 around the top.

*Big kids:* 21 seconds, since it takes 14 seconds there and 7 back. *Bonus:* 31 balls. There are 6 per minute starting at 10 seconds in, then you add 1 more to count the very first.

*The sky’s the limit:* 56,000 yellow sticks, and 14,000 of each of the other 5 colors. If you have equal numbers of those 5 colors and then 4 times as many yellow as any of them, then each red stick has a blue stick, a green, a white, a black and 4 yellow sticks with it, making a “set” of 9. There are 14,000 of those sets in 126,000, so there are 14,000 of each of the small colors and 4 times as many as that for yellow.

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]]>The post Donuts Gone Bonkers appeared first on Bedtime Math.

]]>When you stick one yummy food inside another, you get more yumminess. We have pigs in blankets (hot dogs wrapped in dough), chocolate croissants (chocolate inside buttery bread), and the “turducken,” a Thanksgiving dish where chicken meat is stuffed inside duck meat inside a turkey. Now we have the “donut turducken.” While testing donut recipes, chef Kim Laidlaw stuffed an apple fritter (fried apple pieces) inside pudding inside a donut, which she then coated with chocolate frosting and sprinkles. Cinnamon-flavored apples don’t sound like a great match for chocolate…but it’s probably tastier than stuffing it with duck!

*Wee ones:* If you stuff apples inside pudding inside a donut covered in frosting, how many different foods have you mixed up?

*Little kids:* If you stuff 8 chunks of apple in one donut and 11 in another, which has more apple? *Bonus:* If you stick 3 apple pieces in each donut, will 7 pieces be enough for 2 donuts?

*Big kids:* If guests are visiting you an hour from now, and it takes you 20 minutes to fry the apples, 20 minutes to fry the donuts, and 16 minutes to stuff them, can you make the donut turduckens in time? *Bonus:* If you make 8 donuts in that time (56 minutes), how many minutes did each donut turducken take on average?

Answers:

*Wee ones:* 4 foods.

*Little kids:* The donut with 11 chunks. *Bonus:* Yes! since you need only 6 pieces.

*Big kids:* Yes: they will take 56 minutes, and guests are coming in 60. *Bonus:* 7 minutes each.

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]]>The post Dogs in Charge appeared first on Bedtime Math.

]]>Dogs may seem like they’re just fun, fluffy goofballs. But some dogs actually work real jobs, such as police dogs. They’re called the K9 unit, since it sounds like “canine,” which means “dog-related.” K9 dogs are usually German shepherds, like these dogs here, and they get lots of excitement. They help chase down bad guys, sniff for drugs, and rescue missing people. The dogs can’t talk, so they have to show what they think by doing the right action, like barking or sitting very still next to what they’ve found. These dogs are working on behaving well, by watching a cat without chasing it. K9 dogs train for a few hours every week, and can work for about 6-9 years. Then they can start chasing cats again.

*Wee ones:* Are there more cats or dogs in the photo?

*Little kids:* If a dog trains until age 3 and then works for 7 years, how old is the dog when he stops working? *Bonus:* If an 11-year old dog has worked for 9 years, how old was she when she started?

*Big kids:* If a dog starts training at 9:30 am each day for 8 hours straight, at what time does training end? *Bonus:* If 1/5 of the 15 dogs in the photo just can’t stand it any more and start chasing the cat, how many dogs sit still like they should?

*The sky’s the limit:* If in self-control training there are 5 times as many dogs as cats, and there are 24 animals in total, how many of each animal do we have?

Answers:

*Wee ones:* More dogs!

*Little kids:* 10 years old. *Bonus:* At 2 years old.

*Big kids:* At 5:30 pm. *Bonus:* 12 dogs, since 3 of the 15 dogs pounce.

*The sky’s the limit:* 20 dogs and 4 cats. If there are 5 times as many dogs as cats, then there are 6 total “sets” of animals that add up to 24. That means each set has 4 animals, giving us 1 set of 4 cats, and then 5 times as many dogs, or 5 x 4 = 20.

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]]>The post The People Flying over Your Head appeared first on Bedtime Math.

]]>Have you ever watched an airplane in the sky, and wondered how many people are in there, and where they’re going? Now multiply that by all the planes in the air at any time. This webpage made a 2-minute video showing all the planes that flew over the Atlantic Ocean in 1 day: over 2,500 flights in 24 hours! Air traffic controllers tell the pilots where to fly so they don’t run into each other. So the sky is divided into “tracks” for planes to follow, almost like lanes on a highway. When you run the numbers, you’ll see that there are way more people on that highway than you might think.

*Wee ones:* If you’re the 3rd person to get on a plane, how many people got on before you? Hold up your fingers to show 3 people getting on a plane!

*Little kids:* Planes are spaced to land every 10 minutes. What numbers would you say to count down those 10 minutes? *Bonus:* If 400 flights fly during each busy hour in the morning, how many planes fly in a 2-hour stretch?

*Big kids:* If 7,000 people fly in the morning and twice as many fly during the afternoon, how many fly that stretch in total? *Bonus:* If there were exactly 2,500 flights and they each filled up with 100 passengers, how many people flew over the ocean that whole day?

__Answers:__

*Wee ones:* 2 people before you.

*Little kids:* 10, 9, 8, 7, 6, 5, 4, 3, 2, 1. *Bonus:* 800 flights.

*Big kids:* 21,000 people. *Bonus:* 250,000 people – a quarter of a million!

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]]>The post Lucky 13? appeared first on Bedtime Math.

]]>Today is Friday the 13th, a date that scares a lot of people. They think the number 13 is unlucky, so they worry that bad things will happen today. Many tall buildings don’t even call their 13th floor “number 13” — they skip from 12 to 14! The funny thing is, there haven’t been any more bad Friday the 13ths in history than any other day or date. And even if there had been, why should today follow that? On a happier note, a lot of people have a lucky number: maybe the number of letters in their first name, or a number from their birthday. And as we’ll see here, if people start living life around their lucky number, things can get pretty silly.

*Wee ones:* Think of your lucky number, or just pick a number you like. Try counting up to that number!

*Little kids:* If your lucky number is 9 but your friend’s lucky number is 6, who has the bigger lucky number? *Bonus:* How much bigger is that lucky number than the other?

*Big kids:* If your lucky number is 5, so you clap for good luck 5 times before every soccer game, how many times do you clap in an 8-game season? *Bonus:* If you also eat Cheerios with 5 on the spoon for every bite, how many bites do you need to eat a bowl of 63 Cheerios — with as few non-lucky bites as possible?

Answers:

*Wee ones:* Count 1,2,3…

*Little kids:* Your lucky number is bigger. *Bonus:* By 3.

*Big kids:* 40 claps. *Bonus:* 13 bites, since 12 5’s will get you only to 60.

The post Lucky 13? appeared first on Bedtime Math.

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