## GUESS THE RECORD!

### INTRODUCTION

If you want to know the size of the biggest chewing-gum bubble ever blown or the age of the oldest person in the world, there is only one place to go-the Guinness World Records Web site!

Using the Guinness World Records Web site, pick 2 world records that you find interesting. The records can't just be any records-they must meet the math conditions described below. Make up 4 math clues for each record. A classmate will be using your clues to guess the numbers in your records, so make them good!

pencil and paper

### Part A: Find Your Records

1. Using a search engine, find the Guinness World Records Web site.
2. Browse for facts that interest you on the Web site.
3. Choose 2 records that interest you. Your records must meet these math conditions:
• 1 record must include a number higher than 10 000
• 1 record must be a decimal tenth or a decimal hundredth
• Don't forget that someone else will be trying to guess the numbers in your records so don't ruin the fun. Try to keep your records to yourself.

### Part B: Make Up Clues

1. For each of your records, write a question that will let your partner know what record they are trying to guess. For example, "What is the speed of the fastest train in kilometres per hour?"
2. Create 4 clues for each record you chose. Your clues must involve the following:
• rounding numbers
• describing the place value of digits in a number
• comparing numbers

### Part C: Guess the Record

1. Exchange questions and clues with a partner.
2. Using your partner's clues, find the missing numbers for the records they chose. Write your answers in standard form and words.

1. Check with your partner to find out if you and your partner both guessed the records correctly.
2. Discuss how you could improve your clues.
3. Make any necessary changes to your clues.

### RESOURCES

Guinness World Records Web site

 TASK CHECKLIST Did your records meet the math conditions? Did your clues follow the math rules? Did your clues lead to only one answer? Did you use a variety of math words? Did you include the right amount of detail? Did you write answers to your partner's clues in both standard form and words?