Sticky Fingers

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If you’ve ever looked closely at your own fingertips, you’ve probably noticed that the skin is grooved with very, very thin lines in a spirally pattern.  That’s your fingerprint, and it is your very own: every single person has his or her own special pattern. There are six basic styles of fingerprints, though: loop from right, loop from left, arch, whorl, double loop, and “eclectic,” which basically covers all the weird remaining ones that don’t have a name. These grooves in our fingers help us grip objects — but as a special bonus, fingerprints also leave tracks showing exactly whose fingers they are. You can use your fingerprints on scanners to get permission to open doors, but your fingerprints can also show that you were the thief who opened the cookie jar.  Just one more good reason to wash your hands.

Wee ones: There are 6 types of fingerprints, but half of those involve “loops.” How many loopy fingerprint types are there?

Little kids: If you have messy chocolate all over one hand, and you fully touch the table with that hand 3 times, how many total fingerprint marks do you leave on the table?  Bonus: If 2 friends each have both hands covered with chocolate and they each rest all 10 fingers on the table, now how many total fingerprints are there?

Big kids: One way to see your fingerprint is to press your finger on an ink pad, then on a fresh empty balloon, and then blow up the balloon to watch the design stretch out. If your fingerprint covers a space that gets 5 times as tall and 5 times as wide when you inflate the balloon, how many of your original fingerprint could fit in that new space?  Bonus: If that area now doubles in each direction, now how many times as big is it relative to your original fingerprint?

The sky’s the limit: Suppose your class at school has 12 boys and 12 girls, all with loop, arch or whorl fingerprints.  If half the boys and 2/3 of the girls have loopy fingerprints, and half the remaining kids have arch fingerprints but that includes 3 more boys than girls, how many girls have whorls?

 

 

 

Answers:
Wee ones: 3 loopy types.

Little kids: 15 fingerprints.  Bonus: 35 fingerprints, since the friends added 20.

Big kids: 25 fingerprints.  Bonus: 100 times as big.

The sky’s the limit: 6 boys and 8 girls have loops, leaving 6 boys and 4 girls with other types.  Half, or 5 in total, have arches, but if that includes 3 more boys than girls, then only 1 girl has arches (along with 4 boys). That leaves 3 girls with whorls.

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Water Shooter

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It’s pretty exciting when a volcano explodes and shoots red-hot lava, which is melted rock. Well, nature does this with water, too. A geyser is a rare underground spring that sometimes bursts up through the ground.  One of the most famous geysers is Old Faithful in Yellowstone National Park.  It gets its name because it is very predictable: it erupts every 91 minutes, shooting hot water and steam up to 185 feet in the air for as long as 5 minutes at a time. In the old days, people tried to use Old Faithful to wash their clothes, but found that it was too powerful and the blasting water tore everything to shreds.  Because of changes in the earth, the length of each eruption and the amount of water that comes out have both changed, too. But Old Faithful still deserves its name, as it still shoots boiling water high into the air about every hour and a half – whether you’re waiting to do laundry or not.

Wee ones: If you can spray water out of your mouth for a whole minute straight, but Old Faithful can blast water for 5 minutes straight, how much longer than you can Old Faithful spray?

Little kids:  Is 185 feet about as tall as a person, a building, or a mountain?  Bonus: If the last eruption ended at 3:10 pm, at what time will you see the next one if it’s 91 minutes later? (Reminder: there are 60 minutes in an hour.)

Big kids: For a sense of how tall 185 feet is, you can compare it to other tall things, like a house. If each story adds 10 feet of height and so does the roof, about how many houses with 2 stories and a roof do you have to stack to match Old Faithful?  Bonus: You can also compare to an American football field, which is 120 yards long. About what fraction of a football field standing on end would the highest eruption match? (Reminder: a yard equals 3 feet.)

 

 

 

Answers:
Wee ones: 4 minutes longer.

Little kids: About as tall as a building with 18 floors.  Bonus: 4:41 pm.

Big kids: Each house is 30 feet tall, so you’d need about 6 houses, which stack to 180 feet.  Bonus: A football field is 360 feet high, so 185 feet is about half a football field.

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Cicadian Rhythms

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Okay, let’s get this straight once and for all. We’ve heard that cicadas, those fat grasshoppers that make that loud, high-pitched chirping noise, come around every 17 years. We’ve also heard there’s another type that shows up every 13 years. And the fact is, we feel like we see or hear a couple of them every year. It turns out the 17-year cicada lives in the Northeast U.S. and the 13-year is its Southern cousin.  This year is apparently the big year for the 17-year cicada crowd to come out from underground, lay eggs, and then disappear. If you live in the Northeast and listen carefully while outdoors, you’ll hear the loud, whirring sound they make. Apparently their 90-decibel shriek is as loud as a subway — of course, as one person pointed out, if you’d been stuck underground for 17 years, you’d be screaming, too.

Wee ones: A cicada is an insect and therefore has 6 legs. How many more legs does it have than a person?

Little kids: Were you around when the cicadas last showed up 17 years ago?  Bonus: How old will you be when the 17-year cicadas come again?

Big kids: In what calendar year will the 17-year cicadas return again?  Bonus: Cicadas come out when the weather reaches 64 degrees. If it’s 49 degrees out where you are, how much warmer would it have to be?

The sky’s the limit: If the 17-year cicada shows up, and then 3 years later the 13-year cicada shows up, how many years after that will they both show up the same year?

 

 

 

Answers:
Wee ones: 4 more legs.

Little kids: Different for everyone…see if your age is less than 17!  Bonus: Add 17 to your age today.

Big kids: In 2030.  Bonus: 15 degrees warmer.

The sky’s the limit: Every cycle of the 13-year cicada leaves the 17-year cicada behind by another 4 years. So to start, the 17-year has 14 years to wait. The next time the 13-year shows up, the 17-year is just 1 year behind. Counting from there, it will then be 5 years behind, then 9, 13, and finally 17 years behind, which means they both show up that year. That makes 5 cycles of the 13-year cicada, or 65 years.

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From Soup to Nuts

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Soup is good for you, but it should also be fun to eat. That’s why alphabet soup, soup with little o’s, etc. are all great options. Even better is when your soup is looking back at you. Maybe you’ve tried those Campbell’s soups with noodles shaped like princesses, Phineas and Ferb, or Scooby Doo. Did you ever wonder exactly how many of each character end up in the can? Or whether it’s equal? Did some character not get his fair share of noodles? And what are your chances of getting your favorite character with each bite? It’s time to run some numbers.

Wee ones: If you eat 3 Cinderella noodles, 2 Snow Whites and 2 Ariels, how many princess soup noodles did you eat?

Little kids: If your Cars soup has 22 Maters but twice as many Lightning McQueens, how many Lightnings are in there?  Bonus: How many Maters and Lightnings all together?

Big kids: These soups each seem to have 6 types of noodles. If Campbell’s makes 6 different soups in this series, how many different kinds of noodles do they have to make?  Bonus: If you’re eating soup from just one can, and with each spoonful you pick up either 1 or 2 noodles, how many total different spoonful combos can you scoop?

 

 

 

Answers:
Wee ones: 7 noodles.

Little kids: 44 Lightning noodles.  Bonus: 66 noodles altogether.

Big kids: 36 different noodles.  Bonus: You have 27 types of spoon arrangements: 6 1-noodle possibilities and 21 2-noodle possibilities.

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Digging Out

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As long as we’re talking about vehicles and water, this news story might top the tugboats. A group of travelers in Siberia reached a flooded river that they had to cross, so they got creative. They used two excavators – those earth-diggers with the giant scoop-shaped shovel at one end – to carry everyone across. As you can see in this video, a handful of people at a time climbed into the shovel of one excavator, which then swung its arm out over the river. The other excavator swung its shovel out to meet the first shovel, and the riders climbed from one shovel to the other, handing over luggage as they did. Then the next group climbed in. This can’t be the fastest or easiest way to travel, but at least no one fell in the river – the water in Siberia is pretty darn cold!

Wee ones: If the shovel can hold 8 people and you’re 6th in line, will you get to climb in with the first group?

Little kids: If 8 people can cross the river in the shovel and half those people have luggage, but of the people who have luggage, half have 2 suitcases and the others have just 1, how many suitcases have to fit in the shovel?  Bonus: If it takes 10 seconds for each person to climb in, 11 seconds to switch shovels, and 8 seconds to climb out, how many seconds of climbing does each passenger have to do without falling into the river?

Big kids: That looks like a long line of people waiting to cross…If the shovel holds 8 people and there are 59 people who want to cross, what’s the minimum number of groups the excavators have to ferry across?  Bonus: If another 22 more people show up before they’ve finished, now how many trips will it take – and can you solve that quickly without adding 59 and 22?

The sky’s the limit: If each excavator can swing between shore and mid-river in 5 seconds (whether empty or full), and climbing in takes 10 seconds, the mid-river hand-off takes 20 seconds, and climbing out takes 15 seconds, how long does it take for the whole group of 59 to cross the river IF the first excavator always returns to load the next group of 8 immediately?

 

 

 

Answers:
Wee ones: Yes! And two more can climb in after you.

Little kids: 6 suitcases. 4 people have luggage, and 2 of them have 2 suitcases each while 2 of them have 1 apiece, making 2+4.  Bonus: 29 seconds of climbing.

Big kids: 8 trips, since the first 7 trips will take just 56 people.  Bonus: It will now take 11 trips. The 22 people will fill 2 full trips and have 6 folks left over. 5 of those will fill the 8th trip from the original group, then one poor guy will have to ride alone.

The sky’s the limit: 370 seconds (or 6 minutes 10 seconds). The first group takes 10+5+20+5+15, or 55 seconds to get across. However, each group after that adds a little less time, because when the second excavator swings back to mid-river the 1st excavator is already waiting.  The 2nd excavator needs 5 seconds to swing back, 20 seconds to collect people, 5 to get to shore, and 15 to unload. So you add only 45 seconds for each of the next 7 groups. That makes the total 55 + seven 45′s, or 370 seconds.

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