The post Dog Train appeared first on Bedtime Math.

]]>Dogs love to ride in the car with their head sticking out the window. Looks like they love riding trains, too. Eugene Bostick, an 82-year-old man in Texas, built a dog train that he pulls with his tractor. He takes care of dogs he finds who don’t have a home. When he had just a couple, they’d ride in the tractor with him. But now there are too many dogs to fit in his lap. So he connected a bunch of blue carts, and ta-da, we have a dog train!

*Wee ones:* What shape are the tractor wheels?

*Little kids:* If there’s 1 dog in each cart, how many dogs are in front of the 7th dog? *Bonus:* If there are 8 carts and you ride in the 5th one, how many dogs are behind you?

*Big kids:* If the dogs ride every 4th day starting on Sunday of the 1st week, in what week do they get to ride on a Tuesday? *Bonus:* If the dogs ride twice a week, how many rides do they get in a 52-week year?

Answers:

*Wee ones:* Circles.

*Little kids:* 6 dogs. *Bonus:* 3 dogs are behind you.

*Big kids:* In the 3rd week (Sunday/Thursday, then Monday/Friday, then Tuesday/Saturday). *Bonus:* 104 rides.

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]]>The post Alligators, Windmills, and One Small Ball appeared first on Bedtime Math.

]]>Golf is the grown-up sport where you use a skinny iron stick, or “club,” to hit a very small ball over and over until it goes into a very small hole. The 18 holes are spread out across giant fields of grass, so it takes hours to finish a game. Thankfully, someone invented “miniature golf,” where the holes are much closer to each other — and the ball rolls through fun buildings and toys. Mini golf players have to “putt,” or hit, the little ball through waterwheels, windmills, and fake animals with their jaws wide open. Today is Miniature Golf Day, so let’s celebrate — and let’s hope no real gators show up.

*Wee ones:* If you putt the ball through the alligator’s mouth, then around the castle, then over the bridge, then through the windmill, how many obstacles have you passed?

*Little kids:* If the spinning windmill blocks every 4th player’s ball starting with the 4th, who’s the next player to get blocked? *Bonus:* If you’ve played all 18 holes except the alligator at the end, how many holes have you played?

*Big kids: *If you get through the windmill on just 2 strokes, but then take 4 putts for the alligator and for each of the next 4 animals, how many strokes is that so far? *Bonus:* If you have a final score of 72 after 18 holes, how many strokes did you take per hole (on average)?

*The sky’s the limit:* If you score a “hole in one” (get the ball into the hole on 1 putt) on every 3rd hole starting with the 3rd, and your friend gets a hole in one on every 5th hole starting with the 5th, on how many of the 18 holes does nobody get a hole in one?

Answers:

*Wee ones:* 4 obstacles.

*Little kids:* The 8th player. *Bonus:* 17 holes.

*Big kids: *22 strokes. *Bonus:* 4 strokes per hole.

*The sky’s the limit:* 10 holes. You will score on 6 holes: 3, 6, 9, 12, 15 and 18. Your friend will score on 3 holes: 5, 10 and 15. But you already counted hole #15 in your set. So that makes just 8 holes total, leaving 10 holes with no hole in one.

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

]]>Bed is a quiet place to sleep – but this one is more like a treehouse, ball ramp and jungle gym combined. Eric Strong’s son didn’t want to move from his toddler crib into a big-boy bed, so Eric built the most awesome kid bed ever. Eric started with a loft bed, then added 3 cubbies and a slide onto the end. The bookcase swings open to a secret compartment, and a ball ramp drops golf balls into a bucket, which the kid can haul back up to the top using a rope. It’s 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 A Backwards Day appeared first on Bedtime Math.

]]>A palindrome is a word that is spelled the same backwards and forwards, like toot and racecar. Can you think of any others? It turns out *numbers*can do the same thing — like today’s date! Today is written as 9/19/19, which means the 19th day of the 9th month (September). In fact, we’re just ending a whole stretch of palindrome days, starting with 9/10/19 up to today. Don’t forget, 9/1/19 was a palindrome, too! We’ve been having cool streaks like this for the past few years, like 8/13/18, and 7/12/17…see if can you figure out when they happen, and when they don’t!

*Wee ones:* How do you say “123” in backwards order?

*Little kids:* If you say “221” in backwards order, is it the same or different? How about 454? *Bonus:* How old will you be the next time your age is the same backwards and forwards?

*Big kids:* If you add up all the digits in today’s date (9 + 1 + 9 + 1 + 9), how much greater is the sum than the sum of the digits of this month’s first palindrome, 9/1/19? *Bonus:* The digits of 9/1/19 add up to 20. What’s the next date that will add up to 20 this way?

*The sky’s the limit:* If you’re allowed to write both the month and year as 2 digits, when’s the first year when we won’t have any palindromic dates? (For example, in 2020 you can write February as 02).

Answers:

*Wee ones:* 321.

*Little kids: *221 then reads 122, so it’s not a palindrome. But 454 does work! *Bonus:* Different for everyone…any single digit works, like 7, 8 or 9! Or your next age might be 11, or 22…or 101!

*Big kids:* It’s 9 more. You can actually figure this out without doing any addition – there is one more 9 in today’s date, and all the other digits are the same! *Bonus:* 10/9/19 is the next date with digits that add up to 20. You know it can’t be a September date, because 9/x/19 gives you a sum of 19. October dates give you a sum of 11 between the month and year (10/x/19 = 1 + 0 + 1 + 9 = 11). If 11 + x = 20, then x must equal 9.

*The sky’s the limit:* We’ll have the same kinds of dates in 2019 (/10/19, 9/11/19…), and in 2020 we can have them in February (02/1/20 through 02/9/20, plus 02/11/20). We’ll also have a couple in 2021 (for example: 1/2/21, 1/21/21, and 12/1/21 through 12/9/21, as well as 12/11/21 and 12/22/21). Then in 2022 we’ll have 2/2/22, 2/20/22, 2/21/22 and so on. That’s true throughout the ’20s, with dates like 3/20/23, all the way through 9/29/29. In 2030 we start over with 03/1/30, then 1/3/31. This pattern will continue through the ’40s, ’50s, all the way to 9/9/99 in 2099. 2100 is the first year we won’t have one, because we can’t have 0/0/00!

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]]>The post Toying With a World Record appeared first on Bedtime Math.

]]>Toy cars are tiny, but this one took over a whole road! That’s because the 3-inch car was setting a world record for the longest toy car track. About 50 kids came together to build the bright orange track. The track was made up of 1,400 bendy plastic pieces that stretched for 2,187 feet – almost 1/2 a mile. The car zoomed down the track so quickly, people had to use a golf cart to keep up with it! Maybe toy cars aren’t so different from the real deal after all.

*Wee ones: *Grab a toy car or anything else that rolls. Tap it forward on the floor, then give it a really big push. Which made the car go farther, the tap or the big push?

*Little kids: *If you and a friend ride in a car and each of you brings along a toy car, how many more toy wheels than real ones? (Reminder: Both kinds of cars each have 4 wheels.) *Bonus: *If toy cars are 3 inches long, how many would you need to line up to make 1 foot? (Reminder: 1 foot has 12 inches).

*Big kids: *If the toy car went 17 MPH and the speed limit on the road was 35 MPH, how much faster would the toy car have to go to match the speed limit? *Bonus: *If the 2,187-foot long track was made up of 1,400 identical track pieces, were the track pieces more or less than 2 feet long?

*The sky’s the limit: *1 mile has 5,280 feet and the track was 2,187 feet long. If the toy car traveled at a constant speed of 15 MPH, did it take more than 120 seconds to finish the course?

Answers:

*Wee ones: *The big push made it roll farther!

*Little kids: *4 more toy wheels than real ones. The toys have 4 + 4 = 8 wheels, while the real car has 4. *Bonus: *4 cars, because 3 + 3 + 3 + 3 = 12.

*Big kids: *18 MPH faster to reach a speed of 35 MPH. *Bonus: *Less than 2 feet long, because 2-foot-long track pieces would make 2 x 1,400 = 2,800 feet of track.

*The sky’s the limit: *No, it took less than 120 seconds, or 2 minutes. You can figure out that the track is less than 1/2 mile long, because 1/2 of 5,280 feet is 2,640. Going 15 miles in 60 minutes means it takes 4 minutes to go 1 mile, since 15 goes into 60 4 times. Since the car is travelling less than 1/2 mile, it will travel for less than 1/2 of those 4 minutes.

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]]>The post Hang Out Inside My Piano! appeared first on Bedtime Math.

]]>What shape is your house? Maybe a rectangle with some triangle roof shapes? How cool would it be if it looked like a piano, with a huge violin leaning on it? This cool building was made at the Urban Planning Exhibition Hall in Huainan City, China. The piano has windows all the way around in that stripe, and the violin part holds the stairs that take you inside the piano. You can see how huge a house this is — just look at the tiny people standing at the bottom!

*Wee ones:* What shapes are the windows going around the piano?

*Little kids:* The violin has 4 long bars that look like violin strings. If you pluck the first and last to play them, how many strings are left in between? *Bonus:* If the 4 violin strings are spaced 2 feet apart, how far is the 4th string from the 1st? Think carefully!

*Big kids:* Imagine a house shaped like your favorite toy. If it’s 50 feet tall, how much taller than you is it in feet? Or try feet and inches! *Bonus:* If that person is 6 feet tall, about how high off the ground is the top of the piano lid? Eyeball it and take a guess!

*The sky’s the limit:* If the violin part of the building is 60 times as tall as a real violin and 700 inches taller than 10 violins stacked end to end, how tall are a real violin and this violin building?

Answers:

*Wee ones:* Rectangles.

*Little kids:* 2 strings. *Bonus:* 6 feet, since the 4 strings have only 3 gaps between them.

*Big kids:* Different for everyone…subtract your height in feet from 50, or take away feet and inches to be more exact! *Bonus:* We’re thinking about 48 feet. The piano legs are about twice the person’s height, then the piano is about 3 people’s height, and the lid adds about 3 people’s height.That comes to 8 times the person’s height.

*The sky’s the limit:* 14 inches for a violin, 70 feet (840 inches) for the building. If 700 is the difference between 10 violins and the building, which is 60 violins tall, then that 700 equals the height of 50 violins. Dividing, we get 14 inches for a violin, and 60 times that (840 inches) for the building.

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]]>The post Why Do Cats Have Whiskers? appeared first on Bedtime Math.

]]>Cats look so cute with those furry, fuzzy whiskers. But the whiskers are more than just cute. When they brush against anything, cats really feel it. That helps the cat figure out if it can squeeze through an opening without getting stuck. You never want to cut those whiskers, because it will leave the cat dizzy and confused. The 8-12 whiskers on each side of the nose also show a cat’s mood! Whiskers tilted forward mean the cat is excited and alert. Whiskers flattened back show anger or fear. And whiskers sticking straight out show that a cat is calm – and that’s probably the cutest of all.

*Wee ones:* If a cat has 8 cute whiskers, what numbers would you say to count them?

*Little kids:* If a cat has 10 whiskers on each side of its nose, how many does it have? *Bonus:* What if it has 12 on each side — how many more whiskers does it have now?

*Big kids:* If a cat had 9 whiskers on each side of its nose, above each eye, and behind each front paw, how many whiskers would that be in total? *Bonus:* If 1 cat has 80 whiskers in total, another has 36 in total, and a 3rd cat’s number is halfway between those, how many whiskers does the 3rd cat have?

Answers:

*Wee ones: *1, 2, 3, 4, 5, 6, 7, 8.

*Little kids:* 20 whiskers. *Bonus:* 4 more whiskers since you added 2 on each side.

*Big kids:* 54 whiskers (6 sets of 9). *Bonus:* 58 whiskers. The difference between the first 2 cats is 80-36 = 44, so the 3rd cat’s number will be 22 less than one cat and 22 more than the other cat.

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]]>The post Fruit Fight appeared first on Bedtime Math.

]]>Wait — how can these peaches and cherries grow on the same tree? Well, a guy named Sam Van Aken creates trees that grow lots of kinds of fruit. He “grafts” trees together, meaning he cuts off one tree’s branch and ties it to a cut in another tree’s trunk. If it works, they grow into one happy tree. Peaches and cherries work because they’re cousins — they’re both stone fruits (they have a pit inside). Sam’s trees can bear up to 40 kinds of fruit, and flowers to match! It’s like someone giving you a rabbit’s ears or an anteater’s nose… except a lot better-looking.

*Wee ones:* If Sam’s tree has flowers in white, pink, purple, orange and magenta, how many colors is that?

*Little kids:* If you pick fruit to bake a cherry pie, then a peach pie, then a cherry pie, then a peach pie…what should you bake next to keep the pattern? *Bonus:* How would you count up the tree’s 40 fruits by 10s?

*Big kids:* What if a tree could grow snacks? If your tree grows potato chips, pretzel sticks, and Cheetos, and you pick 1 snack type each day cycling in that order, how many days until you’ve picked 25 of each snack? *Bonus:* If it grows 40 snacks and you pick a new snack each day, then after the 40 you start over in the same order, how many *full* times will you cycle through all snack types in 1 year? (*Reminder:* A year has 365 days; a leap year has 366.)

Answers:

*Wee ones:* 5 colors.

*Little kids:* A cherry pie. *Bonus:* 10, 20, 30, 40.

*Big kids:* 75 days. *Bonus:* 9 full cycles, since that brings you to 360 and you can’t then fit another cycle.

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]]>The post When Cat Meets Deer appeared first on Bedtime Math.

]]>Even though there’s only 1 cat and 4 deer in this picture, all the animals look confused and a little suspicious. It makes sense that the little cat would be nervous. While cats typically weigh 8-12 pounds, deer can weigh 150 pounds. And both animals have a top speed of about 30 miles per hour. The real question is, which one can rule the world? A deer can have 1 to 4 babies in a year, while cats can have up to 12 kittens per year. In the end, cats might take over!

*Wee ones:* How many animals can you count in the photo?

*Little kids:* If a deer and a cat try to race, how many legs do they have together? *Bonus:* Deer antlers can grow 1 inch per day. If *you* grew an inch a day, how tall would you be 1 week from now?

*Big kids:* If the lead deer weighs 200 pounds and the cat weighs just 12 pounds, how many pounds heavier is the deer? *Bonus:* How many cats that size would have to get together to outweigh the deer?

Answers:

*Wee ones:* 5 animals: 4 deer plus the cat.

*Little kids:* 8 legs (4 on each). *Bonus:* Different for everyone…add 7 to your height in inches.

*Big kids:* 188 pounds more. *Bonus:* 17 cats, since 16 cats will weigh just 192 pounds.

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

]]>Today is Friday the 13th! A lot of people think the number 13 is unlucky, so they worry 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 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 their birthday, or the number of letters in their first name. Do you have a lucky number? Let’s check it out!

*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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