The post Rescuing the Big Cats appeared first on Bedtime Math.

]]>If you have a cute little cat as a pet, you don’t have to stop there — why not go bigger? These fellows in Mexico rescue *big *cats, like tigers, lions, jaguars, and cheetahs. Eduardo and his team save these beautiful animals from cruel owners who keep the animals in circuses or badly run zoos. Instead, these big furry friends can now live in peace at the Black Jaguar White Tiger Foundation rescue center. These are big, strong, dangerous cats: lions can weigh more than 500 pounds, and cheetahs can run at nearly 70 miles an hour. You wouldn’t want an angry big cat pouncing on you. But they’re all super-cuddly with Eduardo and each other. They even let the family dog snuggle up and chew on their paws. The center has more than 30 cats living there now, and if there are other big cats in need, hopefully Eduardo will find them.

*Wee ones:* Who has more legs, you or a lion? (All cats have 4 legs.)

*Little kids:* Who’s faster, a 60-mile-an-hour lion or a 70-mile-an-hour cheetah? *Bonus:* Their Babies webpage show 15 pictures of big cats, including 5 that show 2 siblings each (brothers and/or sisters). How many cats are pictured in total?

*Big kids:* If they have 31 cats and then rescue 19 more, how many cats will they have? *Bonus: *How many furry paws do 30 big cats have?

*The sky’s the limit:* If of the 30 cats there were twice as many lions as cheetahs, twice as many jaguars as lions, and 2 tigers, how many of each cat would they have?

Answers:

*Wee ones: *The lion.

*Little kids:* The 70-mile-an-hour cheetah. *Bonus:* 20 cats, since those pairs add 5 extra.

*Big kids:* 50 cats. *Bonus:* 120 paws.

*The sky’s the limit:* There are 16 jaguars, 8 lions, 4 cheetahs, and the 2 tigers. Once we carve off the tigers we have 28 cats. And each set of 1 cheetah, 2 lions and 4 jaguars makes a set of 7. We can fit 4 of those sets of 7 in the 28, so we have 4×1, 4×2, and 4×4 of those animals.

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]]>The post Tic-Tac-Toe with a Twist appeared first on Bedtime Math.

]]>If you’ve played tic tac toe — or noughts and crosses, as it’s called in England — you know the simple idea behind it. Two players take turns writing x’s and o’s on a grid, each hoping to line up 3 in a row. Well, you can make it even more exciting by doing tic-tac-toe times ten: You make a giant tic-tac-toe board, and each square has its *own* little tic-tac-toe board in it. Each time a player wins a board, that whole square now counts as that shape, and the winner is the person who wins 3 *giant* squares in a row. How do you play? When a player fills in any little square, the next player has to go to the mini-board in the matching part of the giant board. So if someone fills in the center box, the other player has to make a move on the center board; if he then fills in the top left square there, the first player must now go to the top left board. As the boards fill up, you have to avoid sending the other player to a board where he or she could win. So it gets tricky. Then you can put each of those big boards in a square on an even *bigger* board…at that point you’d better really like tic-tac-toe!

*Wee ones:* How many spaces does a regular tic-tac-toe board have? See if you can count them all!

*Little kids:* If 5 squares are filled in with x’s and the rest are filled with o’s, how many o’s are there? *Bonus:* If you fill in the top left corner of the board, in how many directions could you win 3 in a row?

*Big kids:* When you have this giant board with a mini tic-tac-toe board in each square, how many tiny squares are there on the whole page? *Bonus:* If you can fill in any square on the center board, and then that player can fill in any square on the next board, how many possible pairs of first 2 moves can the game have?

Answers:

*Wee ones:* 9 spaces.

*Little kids:* 4 o’s. *Bonus:* In 3 directions: across, down, or on the diagonal to the bottom right.

*Big kids:* 81, since it’s 9 x 9. *Bonus:* 80. For each of the 9 squares the first player chooses, it leads to 9 possible choices on the next board EXCEPT if it leads to the center board again, where there are only 8 choices left. So it’s (9 x 9) – 1.

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]]>The post The Truth about Toothpaste appeared first on Bedtime Math.

]]>Brushing your teeth is kind of a weird activity, isn’t it? Who thought it up? Thousands of years ago, Babylonians and Egyptians used “chew sticks,” just twigs they pulled off trees to scrape their teeth. Then about 1,400 years ago the Chinese made a brush out of pig hairs shoved into a bamboo handle. Soon the Europeans tried horse hair instead — the bristles were softer, and who knows, maybe they tasted better, too. Meanwhile, back 2,000 years ago the Egyptians were also rubbing their teeth with a mix of rock salt, mint, ground up flowers, and pepper. The Romans were tough guys and decided to mix in crushed seashells and bones to scrub their teeth harder. For hundreds of years people tried mixing in charcoal, bread, and ashes from fireplaces. So no matter how you feel about brushing your teeth, you can be sure it tastes and feels better than in the old days!

*Wee ones:* If your toothpaste mixes salt, seashells, soot, bones and mint, how many ingredients in your tasty paste?

*Little kids:* If you brush your teeth every night starting Sunday but forget to on the 5th night, which night do you skip? *Bonus:* If you brush twice a day, how many times do you brush in 1 full week?

*Big kids:* If you scrub your brush once tonight, 3 times the next night, 7 times the next, and 15 times the next, what number do you guess you brush the night after that? *Bonus:* If the bristled brush showed up 1,400 years ago, around what year was that? (We’re in 2015 now.)

Answers:

*Wee ones:* 5 ingredients.

*Little kids:* Thursday. *Bonus:* 14 times, since a week has 7 days.

*Big kids:* 31 times, since you keep doubling the number you add: you add 2, 4, 8…then 16. *Bonus:*Around the year 615.

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]]>The post Best of Bedtime Math: Pet Project appeared first on Bedtime Math.

]]>Pets: can’t live with them, can’t live without them. Whether it’s a rambunctious Rover, rascally rabbit, or regular old rock, we’re all fond of our non-human friends. Here are 13 of our favorite stories of pets acting like wild animals – we promise they won’t bring bad luck!

-A group of ferrets is called a “business,” and they definitely get up to some funny business while building airplanes.

-Speaking of silliness, did you know there’s a day just to celebrate dressing up your pets? Maybe you should protect your guinea pig with this real suit of armor.

-Of course, there are fewer things safer than the buddy system – which is why those guinea pigs are required by law to have friends in Switzerland!

-If you’ve never seen baby rabbits before, this is your chance to watch four of them grow up from day one! Once they grow up, those big bunny hoppers can be real showstoppers.

-Who says dogs and cats can’t get along? This tiger and Jack Russell Terrier prove that size difference can’t overcome the craving for cuddling.

-And maybe felines are friendlier than their reputation. After all, they’ve shown they can treat deer dearly, and share a bed – even with (hedge)hogs.

-But if you really want to know where you stand with a cat, just check which way their whiskers are pointing.

-We know dogs are man’s best friend, but which type of dog is the best best friend? Here are the most popular breeds around the world.

-You know a dog’s your pal when he’ll do yoga with you! Meet Pancho, the best-balanced Chihuahua around.

-Finally, this farmer doesn’t need a sheepdog, because he can send hundreds of ducks in any direction he wishes, using only his voice!

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]]>The post A Pumpkin That Packs a Punch appeared first on Bedtime Math.

]]>Here we’ve barely started the month of October, and already the pumpkins are working hard to become the biggest and bestest ever for Halloween. Gene McMullen of Illinois just grew the new largest pumpkin ever in North America: it weighs 2,145 1/2 pounds! As we see in this quick video, it’s a huge job even to lug the pumpkin onto a scale to measure it. Gene must have some special gardening tricks, since he’s the same guy who grew that 1,692 1/2-pound pumpkin last year (we like that he adds on that extra half pound, just to show he’s paying attention). The largest pumpkin in the world weighed 2,323, but we’re thinking Gene is getting good at this and might beat that number next year. That all said, this is one awfully weird-looking shape to carve into a jack-o-lantern.

*Wee ones:* Can you say the digits in the number 2,145?

*Little kids:* Which weighs more, a 1-ton elephant or this pumpkin? (A ton equals 2,000 pounds.) *Bonus:* If it took Gene exactly 5 months to grow this pumpkin as of today, in what month did he plant the seed?

*Big kids:* If next year Gene grows a pumpkin that weighs 200 more pounds than this 2,145-pound one, will he beat the record of 2,323? *Bonus:* If he chops off 10-pound chunks to make pumpkin pie, how many full pies can he get out of it?

*The sky’s the limit:* If the pumpkin weighed 10 pounds after its first week of life, then doubled its weight each week, could it have reached this weight in 10 weeks?

Answers:

*Wee ones:* Two, one, four, five.

*Little kids:* The pumpkin weighs more. *Bonus:* In May.

*Big kids:* Yes! It will weigh 2,345 pounds (a nice neat number). *Bonus:* 214 pies, with 5 pounds of pumpkin goop left over.

*The sky’s the limit:* Yes. It will weigh 20 pounds on the second week, then 40, 80, 160, 320, 640, 1280, and finally 2,560 in the 9th week.

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]]>The post Build Your Own Big Bad Bed! appeared first on Bedtime Math.

]]>Bed may just seem like a quiet place to sleep. But for this kid, bed is more like a treehouse, ball ramp and jungle gym all shoved together by a clever dad. Eric Strong’s son didn’t want to move from his toddler crib into a big-boy bed. But a new baby was on the way, so he had to switch. To talk him into it, his dad built the most awesome kid bed ever. Eric started with a loft bed from Ikea, then added three cubbies onto the end and ran a slide on top of them. Instead of a regular bookcase, he made it swing open as a door to a secret compartment. He even added a ball ramp that drops golf balls into a bucket, which the boy hauls back up to the top by pulling on a rope. It’s all pretty awesome, but we wonder if he ever sleeps!

*Wee ones:* If the boy was 3 years old when the project started but has had a birthday since then, how old is he now?

*Little kids:* The ball ramp tilts and dumps out the balls when all 6 have landed in there. If right now it’s holding 4, how many more balls are needed to tilt it? *Bonus:* If instead there’s an odd number of balls in there, what numbers could that be, if there are 6 at most?

*Big kids:* If the dad put together 20 pieces to make the bed, 4 for the slide, and 15 for the secret compartment door, how many more pieces would have brought the total to 40? *Bonus:* If the boy can climb up and slide down the slide in just 20 seconds, how many times can he slide before bedtime 3 minutes from now? (Reminder: A minute has 60 seconds.)

Answers:

*Wee ones:* 4 years old.

*Little kids:* 2 more balls. *Bonus:* 1, 3 or 5 balls.

*Big kids:* 1 more piece, since there were 39. *Bonus:* 9 times, since he can fit in 3 rides per minute.

And thank you to Bedtime Math fan Cindy B. for sharing this story!

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]]>The post Can a Robot Ride a Bike? appeared first on Bedtime Math.

]]>Do you know how to ride a bike? It looks hard if you’ve never done it: how do people keep from tipping over? But once you learn you never forget how to ride one. Somehow we do keep ourselves from tipping over — and now there’s a robot who can do the same trick. As we see in this video, the remote-controlled robot Primer V2 pushes the pedals just like people do to turn them, and steers the handlebars to keep from falling to either side. It even drags his toe to stop. The “roboticist” who built it, Masahiko Yamaguchi, says it’s the first robot that rides just like a human. Primer can ride at up to 6 miles an hour…let’s see if you can keep up with it!

*Wee ones:* If you ride 8 feet on your bike and Primer rides 5 feet, who rode further?

*Little kids:* If Primer tips to the right, then to the right again, then to the left, then starts the pattern again tipping to the right…which way does the robot tip on the 10th tip? *Bonus:* If Primer can ride at 6 miles per hour and you can ride twice as fast, how fast are you?

*Big kids:* If Primer was able to ride 4 feet without falling over on his first try, then doubled his distance with each new try, how far did he ride in total by the end of the 3rd try? *Bonus:* Primer moves his legs pretty fast to pedal. If he pedals all the way around twice every second, how many times does he pedal in a minute? (Reminder: a minute has 60 seconds.)

*The sky’s the limit:* If Primer rides in a circle at 6 miles an hour and you ride at 10 miles an hour, and you both start at the same point, after how many times around will you pass Primer at the starting point again?

Answers:

*Wee ones:* You rode further!

*Little kids:* To the right. *Bonus:* 12 miles an hour.

*Big kids:* 28 feet. *Bonus:* 120 times.

*The sky’s the limit:* At the end of your 5th trip around. Your speed is 10/6ths of Primer’s speed, but that’s the same as 5/3, so you don’t have to wait till your 10th cycle to meet up at the start.

And thanks to Bedtime Math fan Marc R. for this fun topic!

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]]>The post Teeny Tiny Horse appeared first on Bedtime Math.

]]>Horses are as big as they are beautiful; it would be scary to have one chase after you. But not if that horse barely reaches your knees. In this video we see a 3-day-old baby *miniature* horse chasing its owner because it really, really wants to be petted. When his mama’s head pokes out in the bottom right corner of the screen, we see that she’s really short. too. Even as grown-ups, miniature horses grow to be only about 3 feet tall at the shoulders, and horses under 34 inches fall in their own special group. In the old days mini horses worked in mines, because they were strong for their size but were small enough to fit inside those tunnels. Today, though, most miniature horses enjoy being people’s pets. If you’re looking for something more interesting than a dog, you could have one of these — although you probably don’t want it trotting around your kitchen!

*Wee ones:* What numbers do you say to count a horse’s 4 legs?

*Little kids:* If this was the baby horse’s 3rd day of life and it was a Wednesday, on what day was it born? *Bonus:* If it’s just 1 foot tall at the shoulders and doubled that height twice, how tall would it be at the shoulders then?

*Big kids:* If the mama miniature horse is 46 inches tall in total, how much taller or shorter than you is that? Could she look you in the eye? *Bonus:* When fully grown, standard horses weigh about 1,000 pounds! If a miniature horse weighs just 1/5 of that, how much does it weigh?

Answers:

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

*Little kids:* A Monday, since it’s 2nd day was Tuesday. *Bonus:* 4 feet tall.

*Big kids:* Different for everyone…subtract your height in inches from 46, or subtract 46 from your height. *Bonus:* 200 pounds.

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]]>The post Supermoon Lunar Eclipse! appeared first on Bedtime Math.

]]>Tonight our Moon will do not one but TWO cool things at once: a supermoon lunar eclipse. In any lunar eclipse, the Moon passes exactly behind Earth on the opposite side from the Sun, putting it right in our shadow. It doesn’t get completely blacked out because some light still scatters around Earth, so instead the Moon looks deep orange. Meanwhile, the Moon isn’t always the same distance from Earth as it travels around us: once a year it’s at its closest point, called perigee. That’s about 31,000 miles closer than the Moon’s farthest point from us, making it look bigger and also brighter. By luck, the moon will be at perigee tonight, so it will become a bigger orange ball than in most eclipses. The Moon will be completely in our shadow starting at 10:11 pm New York time, but will start sliding into darkness around 8:00. So step outside and check it out!

*Wee ones:* What shape is the Moon?

*Little kids:* The Moon will spend 2 hours sliding into our shadow, about 1 hour sitting in totality, and then another 2 hours sliding out. About how many hours does the whole eclipse take? *Bonus: *If that all starts at 8:11 pm New York time, will the eclipse finish tonight or tomorrow?

*Big kids:* The next total lunar eclipse won’t happen for another 2 years 4 months. In what year will you get to see that? (We’re in Sept. 2015 right now). *Bonus:* Earth is about 8,000 miles wide. About how many Earths closer is the Moon at its closest point than farthest point?

*The sky’s the limit – literally:* The Moon is full, meaning on the other side of us from the Sun, about every 29 days. If it were *exactly* 29, how many days from now will we have another full moon on a Sunday?

Answers:

*Wee ones:* A circle – or as a 3D shape, a sphere.

*Little kids:* 5 hours. *Bonus:* Tomorrow, since it will end after midnight (in fact after 1 am).

*Big kids:* In 2018, since the extra months will carry us to January of that year. *Bonus:* About 4 Earths.

*The sky’s the limit – literally:* 203 days. Since a week has 7 days and 29 is 1 more than a multiple of 7 (28), each full moon would land on the next day of the week: the next would be on a Monday, the one after that on a Tuesday, etc. So the 7th full moon after this one would land on a Sunday again, giving us 7 x 29 = 203 days (and it will actually come close to that: April 22, 2016 lands on a Friday).

Happy moongazing everyone!

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]]>The post A Bigger, Better Paintball appeared first on Bedtime Math.

]]>“Paintball” is a game where people shoot balls of wet paint at each other, and when the paint hits it makes a big splat. But this picture shows another kind of paint ball: it’s a giant ball of dry paint, and it all started with a teeny baseball. Back in 1977 Mike Carmichael and his son, then 3 years old, painted a baseball blue simply because they wanted a blue baseball. Since then they’ve kept painting new layers of paint onto it. Even though paint spreads thin, it does have a thickness, so when you stack enough layers it starts to add up. Now that little baseball has 25,000 layers of paint, making it almost 14 feet wide. And since paint is heavy, the ball now weighs more than 5,000 pounds! Visitors can paint a layer on themselves, so if you want to head to Indiana, you can be part of the world record for the largest paint ball.

*Wee ones:* When that 3-year-old kid started painting, was he older or younger than you are now?

*Little kids:* The ball actually broke the record in 2004, when it was just 9 feet across. At 14 feet, how much wider is it now? *Bonus:* If it grows that same amount again, can it roll through a 20-foot-wide doorway?

*Big kids:* The ball’s chain can hold up to 11,500 pounds. How many more pounds of paint can this 5,000 ball take before the chain breaks? *Bonus:* 1,200 people visit to check out the ball every year. If 1/10 of them paint the ball, how many people paint it?

Answers:

*Wee ones:* Different for everyone…if you’re older than 3, he was younger, but if you’re 3, you’re the same; if you’re younger than 3, he was older.

*Little kids:* 5 feet wider. *Bonus:* Yes, but barely! It will be 19 feet wide.

*Big kids:* 6,500 pounds. *Bonus:* 120 people.

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