# Lesson 7: Powers of 10

## Getting Started

What's the biggest number you can think of? Can you say it? How do you write it? The bigger that numbers get, the harder they are to say and write. For example, how might you say 646,242,576,192,834,515? What parts or places in this number do you already know? What parts or places do you need to know?

During this lesson, you're going to explore REALLY big numbers. The most important thing for you to know is this: numbers go to infinity. They never stop getting bigger. This means that even if you think you've come up with the biggest possible number, there will always be a bigger one! In fact, no matter how big a number is, it will always be closer to one than to infinity. Crazy, right?

### Stuff You Need

• On Beyond a Million by David M. Schwartz
• calculator
• colored pencils* (Activity 2 - optional)
• fine point dry-erase markers (kit)
• glue or glue stick
• laminated decimal place value chart (kit)
• scissors

* - denotes an optional material that may or may not be needed

• What are powers of ten?
• How do you use powers of 10 to represent really big numbers?
• What is an exponent?
• How do you read and write numbers in exponent form?

### Things to Know

• Powers of 10: numbers made by multiplying 10 by itself (for example, 10 × 10 × 10 = 1,000)

### Skills

• Explain patterns in the number of zeros of the product when multiplying a number by powers of 10, and explain patterns in the placement of the decimal point when a decimal is multiplied or divided by a power of 10

### Introducing the Lesson

Your child will explore and work with really big numbers during this lesson. You can refer to this as "working with powers of 10" and "power counting." Starting at the number 10, your child will multiply by 10 to arrive at numbers beyond a million. While exponents will be introduced, he won't work with them directly until the next lesson. Make sure that your child understands that powers of 10 are not the same as multiples of 10. Powers of 10 are numbers made by multiplying 10 by itself. Examples include 10, 100, 1,000, 10,000, and so forth. Multiples of 10 are products of 10 and another number and include 10, 20, 30, 40, and so on. Some numbers, like 100 and 1,000, are both powers and multiples of 10.