Monday, September 25, 2017

Sunflower Fun

Answers for Crazy Shopping

Starting out: You bid more, since 5 is more than 4, so you'll get to buy them!
Challenge 1: $2 more
Challenge 2: $13
Challenge 3: 23 pairs, since they'd have 24 if they had 2 of each
Challenge 4: $27.98

Experts: 20 different combinations. For each of the 5 colours you wear, there are 4 remaining colours from which your dog can choose.  If you wear red, your dog can wear yellow, or blue, or green, or black, making 4 combos. If you instead wear yellow, then your dog could wear red, blue, green, or black, adding another 4...and so on. By the time you try all 5 colours, you've created 5 sets of 4 combos, making 20 total.

Sunflower fun
Spring is here, and that means our friends the flowers are just around the corner. What's cool is that some flowers do math without even knowing it! Sunflowers always have a certain numbers of petals -- only some numbers can work. There's a special set of numbers where you get each number by adding the 2 numbers before it. You start with 1 and 1, which gives you 2...then 2+1 is 3...then 3 plus that 2 gives you 5...5 plus that 3 gives 8, and so on. They're called the Fibonacci numbers, and sunflowers always have a Fibonacci number of petals! Let's see how big that flower can get.

Starting Out: If the first few Fibonacci numbers are 1, 2, 3 and 5, which number did we skip that we would have said if counting?
 Challenge 1: If the last 2 Fibonacci numbers we got were 5 and 8, what's the next number? (Reminder: You get each number by adding the previous two numbers.) 
Challenge 2: If you have a flower with that many petals and another with 5 petals, how many do they have together? 
 Challenge 3: Can a sunflower have 25 petals?  
Challenge 4: For fun we also have "Tribonacci" numbers, where you add the last 3 numbers to get the next. Since it also starts with 1, 1, and 2, what are the next 3 Tribonacci numbers? See if you can remember all the pieces in your head! 

Monday, September 18, 2017

Crazy shopping!

Answers to Licking Lollipops:
Starting out: The left
Challenge 1: 8, 7, 6, 5, 4, 3, 2, 1 
Challenge 2: It's a lot fewer, thanks to that super-long tongue
Challenge 3: 1 minute 40 seconds, since a minute has 60 seconds
Challenge 4: 500 licks

Experts: The 991st lick. Remember, 999 is the 2nd to last (1,000 - 1), 998 is 3rd to last (1,000 - 2) you subtract just 9 to make sure you include 1,000 as the last.

Crazy shopping!

We use numbers every day with money. Money lets us buy food, clothes, and other things we need, but it can also buy some really weird stuff. On the website eBay, people sell their unwanted stuff to each other, like eyelashes for your car, (you stick them over the front headlights) or sunglasses for your dog (‘Doggles’), as we see here. The catch is, everyone who wants to buy something ‘bids’ on it: they secretly say how much they are willing to pay, and whoever says the biggest number wins and gets to buy it. It all depends how badly your dog wants shades! 

Starting out: If you bid $5 for those Doggles and your friend bids $4, which of you bid more? Who will get to buy them? 

Challenge 1: If you buy a green striped singing stuffed elephant for $6, and someone buys it from you for $8, how much more money do you have now than before you bought it?  

Challenge 2: If someone else suddenly bid $5 more than the $8 bid, how much money will that person pay you?

Challenge 3: You can buy Doggles in 12 different colors. If they have 1 yellow pair in stock but 2 pairs of each of the other colors, how many pairs do they have?  

Challenge 4: The car eyelashes sold for $13.99. If you had bid double that, how much would you have paid for them? (Hint if needed: If they had been exactly $14, how different would your answer be?)

Experts: If you buy 5 pairs of Doggles each in a different color -- say red, yellow, blue, green and black -- and you and your dog each choose a pair to wear, how many different color combos could the two of you be wearing?