The post On the Other Hand… appeared first on Bedtime Math.

]]>*Wee ones (counting on fingers): *How many people in your family are left-handed…and so then how many are right-handed?

*Little kids: *If your class has 23 kids and 4 of them are left-handed, how many right-handed kids are in your class? *Bonus:* If half of those 4 left-handed kids can also write just as well with their *right *hands (meaning they are “ambidextrous”), how many right hands in the class can write?

*Big kids: *About 1 out of every 10 people in the world is left-handed, but of the last 20 presidents, 7 have been left-handed! (and from both parties, interestingly…) How many more left-handed presidents is that than if only 1 out of every 10 had been left-handed? *Bonus:* There was just 1 left-handed president before these 20, which means that only 8 out of our 45 presidents have been left-handed. So how many were right-handed?

Answers:

*Wee ones: *Different for everyone…count the number of lefties, and then subtract from the total number of people in your family.

*Little kids: *19 people. *Bonus:* 21 right hands: the 19 righties, plus the 2 both-handed.

*Big kids: *5 more presidents, as probability says there should have been only 2! * Bonus:* 37 right-handers.

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]]>The post Snowboarding Crow appeared first on Bedtime Math.

]]>*Wee ones:* The snow on the roof is white. Try to spot 4 white things in your room.

*Little kids:* If the crow’s ride starts 3 seconds into the video and lasts for 5 seconds, how many seconds into the video does the ride end? *Bonus:* If the crow slides down the left side of the roof, then the right, then the left, then the right…out of 8 rides, how many will be on the left?

*Big kids:* If the crow starts the ride 9 feet from the edge of the roof and finishes 4 feet from the edge, how many inches did the crow slide? (Reminder if needed: One foot equals 12 inches.) *Bonus:* If a woodpecker, robin and peacock all join in the fun, and a pair of birds ride the lid together, how many possible pairs could it be? (Don’t worry about the order, just the pairs of birds.)

Answers:

*Wee ones:* Items might include bedsheets, socks, underwear, sneakers, and paper.

*Little kids:* At 8 seconds. *Bonus:* 4 rides.

*Big kids:* 60 inches, since it’s 5 feet of sliding. *Bonus:* 6 pairs. The crow can pair with the woodpecker (W), robin (R), or peacock (P): CW, CR, CP. Then W can also pair with the robin or peacock, because we already tried CW. That gives us WR and WP. Finally, the robin has only the peacock left as a partner, giving us 3+2+1 = 6 pairs.

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]]>The post The Tallest Lego Tower Ever appeared first on Bedtime Math.

]]>*Wee ones:* If the tower uses blue, red, green, white and yellow bricks, how many colors is that?

*Little kids:* If you’re in charge of adding 70 bricks onto the tower, and you’re counting the bricks by 10s, what numbers do you say? *Bonus:* The tower was finished on a Wednesday and stood for only 5 days. On what day was it taken down?

*Big kids:* 8 layers of bricks stack 3 inches tall. How many layers stack to 1 foot? (Reminder: A foot has 12 inches.) *Bonus:* If the 450,000-brick tower uses 5 colors equally, how many bricks of each color does it use?

Answers:

*Wee ones:* 5 colors.

*Little kids:* 10, 20, 30, 40, 50, 60, 70. *Bonus:* The following Monday.

*Big kids:* 32 layers. *Bonus:* 90,000 bricks of each color.

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]]>The post When Toilets Fly appeared first on Bedtime Math.

]]>*Wee ones:* How many toilets do you have in your home? Count them up!

*Little kids:* The project leader said “anyone” can strap together a nosecone, a round frame, and 4 fins to make a rocket. How many parts is that? *Bonus:* If you launched a flying vacuum cleaner that flew 29 seconds, and this toilet flew for 38, which one had a shorter trip?

*Big kids:* If the toilet reached its highest point halfway through its 38-second flight, how long into the flight did it peak? *Bonus:* If someone had ridden this toilet rocket, and peeked out for the middle 10 seconds of the flight, how long after takeoff would they have started?

__Answers:__

*Wee ones:* Different for everyone…see what number you get!

*Little kids:* 6 parts. *Bonus:* The vacuum cleaner had the shorter trip.

*Big kids:* 19 seconds. *Bonus:* At 14 seconds (5 seconds before 19, until 5 seconds after 19).

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]]>The post What You’re REALLY Wearing appeared first on Bedtime Math.

]]>*Wee ones:* If your jeans weave together white, blue and black threads, how many colors is that?

*Little kids:* If on your shirt 2 up-and-down stripes cross 2 left-right stripes, in how many places do stripes cross? *Bonus:* What if you cross 3 stripes with 3?

*Big kids:* If the leg of your jeans is 100 threads wide and every other thread is blue, how many threads are blue? *Bonus:* If there are actually 3 colors in a repeating order — blue, white and purple — what’s the greatest number of purple threads there could be?

*The sky’s the limit:* If there are 77 threads across, which one is exactly in the middle?

Answers:

*Wee ones:* 3 colors.

*Little kids:* 4 crossings. *Bonus:* 9 crossings.

*Big kids:* 50 blue threads. *Bonus:* 34 threads, if the very first is purple, because then after 33 sets (bringing us to 99) the 100th will be purple also.

*The sky’s the limit:* The 39th thread. If you had just 76 threads, the 38th would be the end of the first half and the 39th would start the second half — they would straddle the center. Once you bump up to 77 threads, the 39th becomes the middle one, with 38 threads before it and 38 after it.

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]]>The post The Weirdest Fruit You’ve Never Tasted appeared first on Bedtime Math.

]]>*Wee ones:* If you eat 3 apples and a jabuticaba, how many pieces of fruits do you eat?

*Little kids:* If you pick 6 jabuticabas from the tree trunk, then climb up and pull 2 more off the branches, how many have you picked? *Bonus:* If you try all 20 of these fruits *except* the snake fruit because that just doesn’t sound good, how many types have you tried?

*Big kids:* If you try 1/2 of the fruits on this list of 20, then try that snake fruit, how many do you try? *Bonus:* If you bite into a miracle fruit at 6:25 pm, and it makes broccoli taste sweet for the next 17 minutes, what’s the latest you get to taste sweet broccoli?

__Answers:__

*Wee ones:* 4 pieces of fruit.

*Little kids:* 8 jabuticabas. *Bonus:* 19 types of fruit.

*Big kids:* 11 fruits. *Bonus:* Until 6:42 pm.

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]]>The post Reading a Book to Fluffy appeared first on Bedtime Math.

]]>*Wee ones:* What shape is the cover of the book?

*Little kids:* If there are 5 cats, and 6 kids come to read to them one at a time, how many cats get to be read to twice? *Bonus:* How many cats and kids are there in total?

*Big kids:* If dogs could read out loud, and 5 dogs read to 25 cats, how many cats does each dog take if they divide into equal groups? *Bonus:* If each animal can enjoy a book for 15 minutes, and kids sign up for 1 hour at a time, how many pets can each kid read to in that time? (Reminder if needed: An hour has 60 minutes.)

Answers:

*Wee ones:* A rectangle, or possibly a square (4 equal sides — hard to tell from this angle).

*Little kids:* 1 cat. *Bonus:* 11 participants.

*Big kids:* 5 cats per dog. *Bonus:* 4 pets.

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]]>The post Juggling Act appeared first on Bedtime Math.

]]>*Wee ones:* If you juggle a shoe, a phone, a pineapple and a stuffed animal, how many items are you juggling?

*Little kids:* If you’re juggling 5 grapefruits and each hand can hold 1 at most, what’s the fewest grapefruits in the air at any time? *Bonus:* How many watermelons would you have to add in to juggle 2 separate 4-fruit fountains?

*Big kids:* If you juggle 4 carrots and a cucumber in a simple cascade (i.e. always in that order), on what toss do you throw the cucumber for the 4th time? *Bonus:* Out of 50 throws, how many will be carrots?

*The sky’s the limit:* If you’re juggling those 4 carrots and cucumber in a cascade (in that order), and throw the first carrot at 0 seconds, then a new object every 2 seconds, which veggie do you throw at half a minute?

Answers:

*Wee ones:* 4 objects.

*Little kids:* 3 grapefruits, since you can hold only 2 at once. *Bonus:* 3 watermelons, to get a total of 8 fruits.

*Big kids:* On the 20th toss. *Bonus:* 40 carrot throws, since 4 out of every 5 will be a carrot.

*The sky’s the limit:* A carrot. At 30 seconds you will do your 16th throw, since it would have been your 15th IF you hadn’t made your first toss at 0 seconds. That 16th throw is right after 3 complete sets, so it will be a carrot.

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]]>The post Cake on Wheels appeared first on Bedtime Math.

]]>*Wee ones:* A car – even one made out of cake – has 4 wheels. Can you count to 4 out loud?

*Little kids:* The seat of this car is made out of Rice Krispie treats. If the seat is 9 treats wide and 1 treat taller than it is wide, how many treats tall is it? *Bonus:* The cake in the car weighed 595 pounds. If the driver ate 3 pounds of cake, how many pounds would the cake part weigh then?

*Big kids:* If a cake car can go 17 miles in 1 hour, how far can it travel in 3 hours? *Bonus:* You have to be able to eat 9 out of every 10 pounds of a car for it to count as an “edible vehicle”. Would a car made out of 85 pounds of cake and 15 pounds of non-edible parts count as an edible vehicle?

Answers:

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

*Little kids:* 10 treats tall!* Bonus:* 592 pounds.

*Big kids:* 51 miles! *Bonus:* No, if a car weighed 100 total pounds, it would need to be at least 90 pounds of cake to count as edible.

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]]>The post Fine-Dining Dog appeared first on Bedtime Math.

]]>*Wee ones:** *What shape is a plate (usually)?

*Little kids:* If the person’s 2 hands and Mariele’s 4 paws could each hold a fork, how many forks could they hold altogether?* Bonus:* If Mariele takes 5 bites of carrot and 2 bites of potato, and there are 10 bites of food on the plate, how many bites did Mariele leave behind?

*Big kids:* The dog performs for about 3 minutes. If they practice the scene 8 times back to back , how long does that take? *Bonus:* Mariele has to pay for dinner every time. If dinner cost $4.50, how much does she pay for those 8 meals? (*Hint if needed:* Think of $4.50 as four and a half dollars.)

*The sky’s the limit:* The actor can’t see a darn thing while stabbing at the food. In feeding the dog 5 bites of carrot and 2 bites of potato, in how many different orders could Mariele have eaten those? (*Hint if needed:* Think about what number bites the potatoes could be.)

__Answers:__

*Wee ones:* A circle.

*Little kids:* 6 forks. *Bonus:* 3 bites, since she took 7 of the 10.

*Big kids:* 24 minutes. *Bonus:* $36.00.

*The sky’s the limit:* 21 ways. The easiest way to solve this is to think of it as “7 choose 2” — that is, how many ways the 2 bites of potato can show up in the line-up of bites. If the first bite is potato, there are 6 spots for the other bite; then imagine the second bite is potato, with 5 remaining slots for the other bite (since the combo of potatoes for the first 2 bites already got counted), and so on. The result is 6+5+4+3+2+1, or 21 combinations.

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