The post Letting the Cat Out of the Bag appeared first on Bedtime Math.

]]>What does it mean when people “let the cat out of the bag”? It means the truth came out, usually about something someone did wrong. They say it comes from farmers selling pigs hundreds of years ago. Pigs were worth a lot of money, but cats weren’t. So when handing over a live piglet in a thick bag, sometimes a sneaky farmer would slip a cat in there instead. But then he had to hope the cat didn’t pop out and ruin everything before the farmer ran away with the money. So we love this photo of a cat taking a nap *with* a pig. Mortiz is a very friendly pig who greets everyone who visits his farm, and he’s buddies with all the other animals there, including this kitty. If you watch the video, you’ll see the cat is actually patting the pig to put him to sleep. Looks like it’s hard work being either a cat or a pig, whether you’re in or out of the bag.

*Wee ones:* Who has more legs, a cat or a pig?

*Little kids:* If the cat and pig fall asleep at 2 pm and nap for 3 hours, will they be up in time for dinner at 6 pm? *Bonus:* Cats eat about 1 ounce of cat food for every pound of body weight each day. If this kitty weighs 10 pounds, how much food does it eat in a week?

*Big kids:* A domestic pig can weigh more than 700 pounds! If this one weighs just 400 pounds and the cat weighs 10 pounds, how many cats would have to pile up to match the pig? *Bonus:* If the pig then peed and weighed 1 pound less, how much would it weigh?

Answers:

*Wee ones:* They’re the same! Each animal has 4 legs.

*Little kids:* Yes, since they’ll wake up at 5 pm. *Bonus:* 70 ounces.

*Big kids:* 40 cats. *Bonus:* 399 pounds.

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]]>The post Get in Line – with Saturn and Mars appeared first on Bedtime Math.

]]>Our planet Earth isn’t the only ball of rock whizzing through space. There are 7 other major planets gong around the Sun — Mercury, Venus, Mars, and so on. Then there’s our Moon. It’s a quarter million miles away, which sounds far. But someone figured out that if you lined up all the other planets, they’d fit perfectly between us and the Moon! They’d leave only 5,000 miles extra, so even Pluto could fit if it still counted as a major planet.

*Wee ones:* What shape are Earth, the Moon, and our planet friends?

*Little kids:* How many objects can you count in the photo of Earth, Moon, and the planets? *Bonus:* Mercury is about 3,000 miles wide, Venus is about 7,000, and Mars is about 4,000. How much of that line-up do those 3 cover together? (*Hint:* You can add 3 thousand, 7 thousand, and so on as if you were adding 3 apples, 7 apples…)

*Big kids:* Jupiter is almost 300,000 miles around at its widest point. How many 3,000-mile-wide Americas could you wrap around Jupiter? *Bonus:* If Earth is 8,000 miles wide and Jupiter is 88,000 miles wide, how many times as wide is Jupiter?

*The sky’s the limit — for real:* If you wanted to line up the 4 gas giants (Jupiter, Saturn, Uranus and Neptune) in the last 4 slots but in some other order, how many other ways could you line them up?

Answers:

*Wee ones:* They are spheres, another word for ball. From the side, they look like circles.

*Little kids:* 9 objects. *Bonus:* 14,000 miles, nowhere near the width of the next biggest planet after Earth (Neptune at over 30,000 miles).

*Big kids:* 100 of them. *Bonus:* 11 times as wide.

*The sky’s the limit:* 23 other ways. If you keep Jupiter first, there are 3 planets that can go in the next slot; for each of those 3 choices you can put either of the remaining 2 planets in the next slot, leaving the last one for the last spot. That gives you 3x2x1 or 6 orders that put Jupiter first. But you can do this with any of the 4 planets coming first, so that gives you 4x3x2x1, or 24 orders. The one shown here is one of them, so that gives us 23 other ways.

And thank you Emily B. for sending these amazing photos!

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]]>The post Speedy Scooter Dog appeared first on Bedtime Math.

]]>We’ve seen dogs ride skateboards and surfboards, which takes great balance. But for a dog to ride a *scooter* is a different story. The pooch has to stand on just 2 legs, hold the handlebars, and then push with one back leg. Well, a French sheepdog named Norman became really good at this, and set the doggie scooter-riding world record. He zipped across a gym floor for 30 meters (about 98 feet) in just 20 seconds, without falling over or having to stop to pee. Norman’s human friends had to train him to understand certain words: “up” to get on the scooter, “scoot” to push with his feet, and “coast” to relax when he’s picked up speed. But judging from the photo, Norman is happy to do this sport without being told.

*Wee ones:* If Norman understands the words “up,” “scoot” and “coast,” how many words has he learned?

*Little kids: *If Norman trained for exactly 3 months and set this record in July 2013, in what month did he start training? *Bonus: *Norman scootered 98 feet. How many more feet would he have to scoot to reach 100 total?

*Big kids:* If Norman had scootered a full 100 feet in 20 seconds, about how long would it take him to go 1000 feet? *Bonus:* If on his 98-foot ride Norman had stopped every 20 feet to sniff the bystanders for 3 seconds, how much longer would his ride have taken?

*The sky’s the limit:* 22 feet per second is the same as 15 miles per hour. If Norman scootered 100 feet in 20 seconds, about how many miles per hour was he going?

Answers:

*Wee ones:* 3 words.

*Little kids:* In April of that year. *Bonus:* 2 more feet.

*Big kids:* 200 seconds, which is 3 minutes 20 seconds. *Bonus:* 12 seconds longer, since he would have stopped 4 times (at 20 feet, then 40, 60, and 80).

*The sky’s the limit:* 100 feet in 20 seconds equals 5 feet per second. So his speed is 5/22nds of 15. That comes to 75/22, which is just shy of 3 1/2 miles per hour.

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]]>The post A Penny a Day Keeps the Dentist Away appeared first on Bedtime Math.

]]>A penny doesn’t buy much – maybe half a bite of a candy bar. So why do we bother carrying them around? Because most things at a store don’t cost an exact number of dollars; they might cost $2.18, or $5.99. And pennies are worth something if you save up giant piles of them. A man who saved pennies for 45 years ended up with thousands of dollars of them! Otha Anders decided he’d save every penny he found or got as change at the store. He finally brought them to the bank so he could pay his dentist, and they added up to $5,136.14! So Otha had his teeth cleaned, and had leftover money to buy a LOT of candy bars.

*Wee ones:* If you have 7 pennies in your pocket and you find 1 more, how many do you have now?

*Little kids:* If you find a penny starting on a Wednesday, and find another one every day until the last one on Monday, how many pennies do you find in total? *Bonus:* If you save the 2nd penny you find, then the 4th, then the 6th…what number penny is the 5th coin you save?

*Big kids:* How many pennies did Otha save if they were worth $5,136.14? *Bonus:* If Otha had saved 3 pennies a day for 45 years, would that have come to as much? (You can round off to estimate… there are 365 days in a year, but see if you can solve it without multiplying big messy numbers.)

Answers:

*Wee ones:* 8 pennies.

*Little kids:* 6 pennies. *Bonus:* The 10th penny.

*Big kids:* 513,614 pennies! *Bonus:* It would not have been enough. With 365 days in a year, 3 pennies per day is about 1,000 for the year. So in 45 years he would have collected about 45,000 pennies or $450 — nowhere nearly enough. Even 30 per day wouldn’t have been enough!

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]]>The post The Straw That Broke the Gator’s Back appeared first on Bedtime Math.

]]>Hey, is that a real live monster-sized alligator? Luckily, no. It’s an alligator made of rice straw. Every year in Japan the people harvest the rice, which leaves straw that you can’t eat. So they bundle and braid the straw into GIANT animal sculptures. Judging from the bridge, this full-length alligator is probably over 10 feet tall and 30 feet long, about twice as long as a car! The artists also made a giant lion, gorilla, and other animals — check them out here! And how much straw do they use? What do they weigh? Let’s do the math to find out.

*Wee ones:* What shape do the alligator’s teeth look like?

*Little kids:* Are there more big teeth or small teeth in the alligator’s top jaw? *Bonus:* How many more big teeth than small teeth does the top jaw have?

*Big kids:* If there are 5 giant sculptures and each used 200 bales (box-shaped bundles) of straw, how many bales were used? *Bonus:* If a bale weighs 40 pounds, how much does a 200-bale animal weigh?

*The sky’s the limit:* A sculpture uses a “mystery number” of bales. We can’t tell you what it is, but if you take that number, add 10, then divide by 10, then square that number (multiply that number by itself), you get 361. What’s the mystery number?

Answers:

*Wee ones:* A triangle (from the side view), or in 3D, a cone (rounded pointed shape).

*Little kids:* There are more big teeth. *Bonus:* 4 more teeth, since we see 8 big teeth and 4 smaller teeth.

*Big kids:* 1,000 bales. *Bonus:* 8,000 pounds!

*The sky’s the limit:* 180 bales. Working backwards, we need the square root of 361, meaning a number that multiplies by itself to get 361. Your clues are that it’s near 400, which is 20×20, and it ends in a 1…only numbers ending in 1 or 9 can multiply by themselves and still get a 1 at the end. That gives us 19. We divided by 10 to get there, which gave us 190; and we added 10 to get there, which gives us 180.

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]]>The post When Sheep and Trains Fly appeared first on Bedtime Math.

]]>What’s that funny-looking bug, and that big smiley sun? They’re hot air balloons — just like balloons at a birthday party, except they’re huge and they’re full of hot air. They’re flying in the Albuquerque International Balloon Fiesta running all this week. Hundreds of hot air balloons fly each day, including crazy ones shaped like chickens, cows and trains. The hot air balloon is a pretty simple idea invented in 1783 in France, when a sheep, a duck and a rooster flew on one. A flame in the basket at the bottom heats the air in the balloon. So that air weighs less than the sky air around it, which makes the balloon float up. Thanks to that trick, now any 4-legged animal can fly.

*Wee ones:* If a sheep, a duck and a rooster flew that very first hot air balloon, how many animals flew it?

*Little kids:* If there’s a cow balloon, a sheep balloon and a chicken balloon, how many legs do they have? *Bonus:* While the fly-around-the-world speed record is 13 days, the longest balloon ride took 19 days. How much shorter was the fastest trip?

*Big kids:* If your rocket balloon can lift 500 pounds and the folks on board already weigh 420 pounds together, how much can you weigh and still ride with them? *Bonus:* The height record for a hot air balloon is 21,000 feet — above that, the pilot needs an oxygen tank since the air is too thin for breathing! If your balloon can fly to only 1/2 that height, how high can you fly?

Answers:

*Wee ones:* 3 brave animals.

*Little kids:* 10 legs (4+4+2). *Bonus:* 6 days shorter.

*Big kids:* 80 more pounds. *Bonus:* 10,500 feet.

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]]>The post Flashing Those Lego Feathers appeared first on Bedtime Math.

]]>Anyone who’s played with Lego knows you can build amazing creations from those tiny bricks. But artist Sean Kenney has taken this toy to the wild side. He makes giant Lego animals that almost look real, they’re so colorful and perfectly shaped. This 5-foot-wide peacock uses more than 68,000 pieces of Lego! His spotted leopard uses 31,000 pieces, and a polar bear with her cubs uses a whopping 125,000 bricks. The heaviest animal Sean has built weighs 400 pounds all by itself — which might be why Sean now owns more than 4 tons of Lego. Click here to see more of Sean’s brick critters!

*Wee ones:* If the mama Lego polar bear has 3 cubs, how many bear family members did Sean build?

*Little kids:* The peacock tail uses 3 shades of blue, 4 shades of green, a grey and a brown. How many colors is that? *Bonus:* If you stack a blue brick, then a green, a grey, and a brown, then start over with blue to repeat, what color is the 13th piece?

*Big kids:* If Sean owned exactly 4 short tons of Lego, how many pounds would that be? (A short ton has 2,000 pounds.) *Bonus:* If you build your own Lego anteater, and the number of bricks is halfway between the 32,000-piece leopard and the 60,000-piece butterfly, how many pieces do you use?

*The sky’s the limit:* Quick: if each row of the peacock’s eyes has 2 more eyes than the row before, and 3 touching rows have 48 eyes, how many eyes does the longest row have?

Answers:

*Wee ones:* 4 polar bears.

*Little kids:* 9 colors. *Bonus:* Blue.

*Big kids:* 8,000 pounds of Lego. *Bonus:* 46,000 pieces. The other two animals are 28,000 pieces apart, so yours is 14,000 more than the leopard and 14,000 less than the butterfly.

*The sky’s the limit:* 18 eyes. If all the rows were the same, they’d each have 16 eyes (48 divided by 3). We can then just shift 2 eyes from one row to another to get 14, 16, and 18.

And thank you Sean for letting us share your incredible pictures!

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]]>The post When Hippos Hang by a Hair appeared first on Bedtime Math.

]]>No matter what crazy question you ask, some scientist has probably studied it. So if you’re wondering how strong your hair is, you’re in luck. It turns out that just one skinny hair on your head can hold up to 3 ounces, which is about 34 pennies! Better yet, a person’s head has up to 150,000 hairs on it. So even if each hair isn’t holding 3 ounces itself, all together your whole head of hair can hold up 15,000 pounds or more, which is about 3-4 hippos (if for some reason you wanted to do that). Even crazier, your hair grows about 1/2 inch a month…if you lay those 150,000 hairs end to end, during one year you grow over 10 miles of hair! That could hold a LOT of hippos.

*Wee ones: *If you try to pick up 4 hippos with your hair, what numbers do you say to count them?

*Little kids:* If 4 hippos are swinging from your hair and 2 more hippos want to join the fun, how many hippos do you have now? *Bonus:* If you could pick up 40 pennies with 1 strand of hair, how would you count those up by 10s?

*Big kids:* If a helicopter rescues you by lifting you by your hair, and each hair can hold 1/5 of a pound, how many of your own hairs do you need for the job? *Bonus:* If your hair can hold up to 30,000 pounds without breaking, how many 4,000-pound hippos could you hold up?

Answers:

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

*Little kids:* 6 hippos. *Bonus:* 10, 20, 30, 40.

*Big kids:* Different for everyone…you need 5 hairs to pick up 1 pound, so multiply your weight in pounds by 5. *Bonus:* 7 hippos, since that comes to 28,000 pounds; 8 hippos would tip you past 30,000.

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]]>The post Fluffy Robot Penguin appeared first on Bedtime Math.

]]>It’s hard to study penguins as a scientist. For one thing, penguins live only in Antarctica or nearby; in winter it’s dark all day and the average temperature is 72 degrees below zero. Also, humans make penguins nervous, making it hard to study penguins’ real heartbeat — their hearts beat faster when they’re worried. So scientists built a small robot to hang out with the penguins to measure these things. But the robot made the penguins nervous, too. Finally the scientists made the robot *look* like a penguin, all cute and furry, and that solved the problem. Some penguins have even tried singing to it. The robot doesn’t sing back, but it learns a lot about the penguins, and doesn’t get cold while doing it.

*Wee ones:* What shape are the wheels on the robot penguin?

*Little kids:* If the robot penguin you see here has 2 wheels on this side, 2 on the other, and a spare underneath, how many wheels does it have? *Bonus:* If there are 8 grown-up penguins, 3 baby penguins, and 2 of these fluffy robots, how many real and fake penguins are there in total?

*Big kids:* Right now the South Pole is heading into summer, so it’s a nice warm -15 degrees by midday. How much warmer than -72 is that? *Bonus:* If there are twice as many penguins as robots and the real penguins have 44 feet in total, how many robots are there?

*The sky’s the limit:* We can’t tell you how many penguins are hanging out with this robot…but if you take that number, double it, add 2, and divide by 5, you get 46. How many penguins are there?

Answers:

*Wee ones:* A circle.

*Little kids:* 5 wheels. *Bonus:* 13 penguins.

*Big kids:* 57 degrees warmer. *Bonus:* 11 robots, since there are 22 penguins.

*The sky’s the limit:* 114 penguins. Working backwards, if we divided by 5 to get 46, the number before that step was 230. We added 2 to get there, so we had 228. We doubled the number to get to 228, so we started with 114.

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]]>The post How Many Days Old Are You? appeared first on Bedtime Math.

]]>It’s amazing how when you do something every day, the numbers really add up. Think of something you do once a day every day…tying your shoes, walking your dog, eating your favorite snack. Over 3 months you’ll do that thing almost 100 times. Over 3 years, you’ll do it more than 1,000 times! That’s because there are 365 days in a year, which is about a third of a thousand. If you do it *more* than once a day — say, 3 times — then you need to multiply by that factor, too. When you use this math to figure out how many days or months you’ve lived, you see that the zeroes add up fast!

*Wee ones:* How old are you in years? Count up to that number with a grown-up!

*Little kids:* If you sneeze once a day every day, how many times do you sneeze in 1 week? *Bonus: *If you walk your new puppy twice a day, how many times do you do that in 1 week?

*Big kids:* If you eat 5 Oreos every day, about how many do you eat in 6 months? (*Hint if needed: *First, about how many do you eat in 3 months?) *Bonus:* If it takes you 100 days to learn to skateboard and you start learning in the beginning of June, in what month can you finally do it?

*The sky’s the limit:* If you live about 1,000 days every 3 years, about how many days have you lived so far?

Answers:

*Wee ones:* Different for everyone…count 1, 2, 3 etc. up to your age!

*Little kids:* 7 times. *Bonus:* 14 times.

*Big kids:* About 1,000 Oreos, since it’s about 100 x 5 x 2. *Bonus:* In September (3 months later).

*The sky’s the limit:* Different for everyone. Divide your age by 3 to find out how many sets of 3 years you’ve lived; that’s how many sets of about 1,000 days you’ve lived. If you have an extra year or two, you can add 365 for each of those. And feel free to tack on extra months, too!

The post How Many Days Old Are You? appeared first on Bedtime Math.

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