Bouncy Dice Explosion The Big Idea 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 Rock n Roll Bingo Numbers: 1 set You provide: Stickers: 10 per 2 kids Pieces of paper: 1 per kid Large writing surface, e.g. blackboard or piece of paper Room Set-up: You ll need open space, at least a 6 x 6-foot rectangle, to toss the dice and to set up Rock n Roll Bingo. If you have extra space beyond that, you can set up the Rock n Roll Bingo numbers ahead of time as described below. What s the Math? Addition Multiplication Strategic thinking Simple combinatorials Simple probability (as fractions) 2013-16 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 angled 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. Ask the kids: What do you notice about the numbers on opposite sides of the dice? See if they catch that opposite sides always add up to 7! 2. Now collect the dice from everyone. Stand in the middle of a cleared area and toss all the dice high into the air. 3. Once the dice stop bouncing, have each kid choose a die. 4. Each kid counts the dots facing up. Kids who got the same number stand together. Count the kids in each group to find out how many times each number was rolled. Explain that this is the frequency of each number in the set. Ask the kids: 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): Ask the kids: How often should each number show up? Discuss as a group. Then explain probability: Each of the 6 sides has an equal chance of facing up, so it must be 1/6 chance for each. So each number (1, 2, etc.) should show on about 1/6 of the dice on the floor. Calculate that answer for your number of dice! 2
War of the Dice (15 minutes) Note: If you re running low on time (less than 25 minutes left), 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 of kids 10 stickers. 4. Each player rolls 2 dice and multiplies the 2 numbers (to get the product). 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. Ask the kids: How often did each person win or lose? (Discuss) Each person has an equal chance of winning, so it should be 1/2 the time for each of 2 people, and 1/3 of the time for 3. Why? What s the lowest product you could have rolled (from multiplying the two numbers)? What s the highest? What do those products have in common? Discuss both 1 and 36 are perfect squares: you can multiply a number by itself to get that answer (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 (25 minutes) Intro to the kids: Who likes playing Bingo? Today we re going to jazz it up. First of all, you re going to play on a giant Bingo board, where you are the chips. Secondly, you ll get to roll 3 dice and choose where to stand based on the numbers you roll! When 5 people are standing in a straight line and yell Bingo! they win. 1. Shuffle the Rock n Roll Bingo Numbers and set them out on the floor in a 5x5 grid, with the Bedtime Math free space in the middle. Example à 2. 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. 3. If none of the numbers or sum of the dice match an open square, the player may roll again. 4. 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. 5. Repeat for each player in line. 6. If you run out of players before anyone can yell Bingo!, use shoes or other objects as placeholders. The players can start rolling again from their places, in their original order. 7. The first 5 kids to form a row yell Bingo! and win the round. Ask the kids: 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) How can you use this to boost your chances of being in a winning row? Discuss see if anybody mentions choosing a row with 4
numbers that many different combos of dice can make, like 9, 10, and 11 and not a row with numbers 17 or 18, which fewer combos can make (3 combos and 1 combo, respectively). What are all the ways you can roll a 3 using all the dice? See if the kids discover it s like 18 with only one combo - 1, 1, and 1. How about a 4? Let the group talk it through and realize that it s just as unlikely 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? Discuss. Write down the kids suggestions on a blackboard or piece of paper. See if they can get the 6 rotations of these combos: 1-2-6, 1-3-5, 2-3-4, the 3 rotations of these combos: 1-4-4, 2-2-5, and the only rotation of 3-3-3 (for a total of 25 ways to roll it). Bonus (optional): Ask the kids: So if 3 and 18 have matching probability, and 4 and 17 have matching probability that s more likely than 3 and 18, which totals will be the most likely to roll? Discuss let the kids discover that 10 and 11 are the most likely sums, 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! 8. Repeat the game as time and interest allow, making sure every player gets to roll at least once. 5
A Touch of Class To the kids: We were on a roll today with the math! And it s a lot like the math you see in class: You roll 2 dice and they turn up the same number. What are all the possible products you can get by multiplying the 2 dice? (Answer: 1 (1 x 1), 4 (2 x 2), 9 (3 x 3), 16 (4 x 4), 25 (5 x 5), and 36 (6 x 6).) If you roll a die, what are the chances it will show an even number? (Answer: 1/2, since 3 of the 6 sides are even numbers.) Each kid can take home 2 bouncy dice to keep rolling with the math fun! 6