The Big Idea Bouncy Dice Explosion This week you re going to toss bouncy rubber dice to see what numbers you roll. You ll also play War to see who s the high roller. Finally, you ll move onto a giant human Bingo board, where you ll roll 3 dice and pick any number that could win! Supplies Bedtime Math provides: Bouncy rubber dice: 2 dice per kid To print: Rock n Roll Bingo numbers You provide: Stickers: 5 per kid Paper cut in half: 1/2 sheet per kid Room Set-up: You ll need open space so the dice can really bounce. Other Key Prep: Print 1 set of the Rock n Roll Bingo numbers on 8 1/2x11 paper best if in color and on cardstock. What s the Math? Addition Multiplication Strategic thinking Bonus: Combinatorials Bonus: Probability (as fractions) "2013'14"Bedtime"Math"Foundation."All"rights"reserved.
Kickoff Intro to the kids: Dice don t really roll, do they? Since they re cubes, with straight lines and pointy corners, they bounce and tumble instead of rolling like a ball. Today we ve got some really bouncy dice to toss! Going Airborne (10-15 minutes) Intro to the kids: First let s see what dice look like, and how far these dice can fly. 1. Hand 1 die to each kid. Have everyone count the sides and edges of the dice. What do you notice about the numbers on opposite sides of the dice? See if they figure out that opposite sides always add up to 7! 2. Collect the dice from everyone. 3. Stand in the middle of a cleared area and then toss all the dice up into the air, letting them bounce everywhere. 4. Once the dice stop bouncing, have the kids tally up how many times each number (of dots) landed face-up in the explosion. Explain that this is the frequency of each number in the set. Which number showed up the most often? What s the smallest total number of dots we could have rolled? What s the highest total? Bonus (optional): How often should each number show up? Discuss as a group. Then explain probability: Each side of a die has a 1/6 chance of facing up. So each number of dots (1, 2, etc.) should show on about 1/6 of the dice. Let s calculate that number! What should be the total number of dots that turn up? The average number of dots on a side is 3 ½, so it should be 3 ½ times the total number of dice. 2
War of the Dice (10-15 minutes) Note: If you re running low on time (20 minutes left or less), skip ahead to Rock n Roll Bingo you won t want to miss it! Intro to the kids: Has anyone played the card game War? If you have, can you tell us how to play? (Discuss ) In our bouncy dice version of War, you re going to roll dice instead of flipping cards! 1. Have kids pair off with new partners and spread out on the floor. If you have an odd number of kids, you can make 1 group of 3. 2. Give each kid 1 pair of dice and 1 piece of paper. 3. Give each pair or group 10 stickers. 4. Each player rolls 2 dice and multiplies the two numbers that show. 5. The player who rolls the higher product wins 1 sticker from the sheet and sticks it to his/her paper. 6. In case of ties, there s no winner - simply roll again. 7. Have kids roll until all the stickers have been won. How often did each person win or lose? Discuss... Each person should win about half the time. Why? What s the lowest product you could have rolled? What s the highest? What do those products have in common? Discuss Both 1 and 36 are perfect squares (1x1, 6x6). More importantly, there s only 1 way to roll each one: a 1 and a 1, or a 6 and a 6. So you have a low probability of rolling them. 3
Rock n Roll Bingo (20-25 minutes) Intro to the kids: Who likes playing Bingo? Today we re going to jazz up Bingo in 2 ways. First of all, you re going to play on a giant Bingo board, where you are the chips. When 5 people are standing in a straight line and yell Bingo! they win. Secondly, you ll get to roll 3 dice and choose where to stand based on the numbers you roll! 1. Shuffle the number squares and set them out on the floor in a 5 x 5 grid, with the Bedtime Math free space in the middle. Example! 2. Smaller clubs may use a 4x4 grid without a free space. 3. The first player rolls 3 dice and decides where to stand: on a number shown on any 1 die, OR the sum of any 2 dice, OR the sum of all 3 - their pick! Encourage the players to work together to choose the best move. 4. If none of the numbers or sum of the dice match an open square, the player may roll again. 5. If the dice add up to 16, 17, or 18, the player can instead choose to go to the free space if your grid has it. 6. Repeat for each player in line. 7. If you run out of kids before anyone can yell Bingo! use random small objects as placeholders. The players can start rolling again in the same order. 8. The first 5 kids to form a row yell Bingo! and win the round. What do you notice about the rolls and the spaces on the board? Are some spaces less likely for people to land on? Why? Discuss. Can you use this knowledge to boost your chances of being in a winning row? Answer: Yes! 9, 10 and 11 will be the most likely totals, because so many different combos of dice can add up to 4
those totals. 18 almost never shows up because only a 6, 6, and 6 will make that. 17 has only 3 combos: 6, 6, and 5, or 6, 5, and 6, or 5, 6, and 6. You want a row with easy-to-roll numbers! What are all the ways you can roll a 3 using all the dice? Answer: It s like 18 in that there s only 1 combo: 1, 1, and 1. How about a 4? Answer: It s just as hard as rolling a 17: it s the 3 rotations of 1, 1 and 2. To compare, what are all the ways you can roll a 9 using 3 dice? Answer: The possibilities are the 3 rotations of EACH of these combos: 1-2-6, 1-3-5, 1-4-4, 2-2-5, 2-3-4, and 3-3-3, for a total of 18 ways to roll it compared to just 3 possibilities for 4 or 17. Bonus (optional): So if 3 and 18 have matching probability, and 4 and 17 have matching probability and it s more likely than 3 and 18, which totals will be the most likely to roll? (Discuss) Answer: 10 and 11, since they re in the middle of the range from 3 to 18. Extra bonus (optional): If anyone wants to figure out all the combos for 10 or 11, go for it! 9. Repeat the game as time and interest allow, making sure every player gets to roll at least once. When you re done, each kid gets to take home a pair of dice! 5