Lesson 3: Digits to the Left and Right


Activity 1: Working With Whole Numbers

Materials: calculator, Interactive Notebook
Read the information and answer the questions on the "Digit Values" sheets. When you get to the second sheet, remember that a fraction is just another way to show division. So, 1/10 means "1 divided into 10 pieces" or "1 divided by 10." When you've finished reading both sheets, you can store them in your Interactive Notebook.
Student Activity Page
Student Activity Page
During this activity, your child will read information and answer questions to solidify his understanding of how values change when we move left and right in whole numbers. He'll review that a fraction is another way to write a division sentence. So, 1/10 means "1 divided into 10 pieces" or "1 divided by 10."

Answer Key:

  • 3 × 10 = (30)
  • 30 × 10 = (300)
  • 300 × 10 = (3,000)
  • 3,000 × 10 = (30,000)
  • 30,000 × 10 = (300,000)
  • What happens each time you multiply by 10? (the number gets 10 times greater/another 0 is added to the end of the number)
  • 342,560 — two thousands, 2,000, or (2 × 100)
  • 428,901 — two ten thousands, 20,000, or (2 × 10,000)
  • How many cents is this? (100 cents)
  • What is 1/10 of this group of dimes? (one dime) How many cents is this? (10 cents)
  • 400,000 ÷ 10= (40,000)
  • 40,000 ÷ 10= (4,000)
  • 4,000 ÷ 10= (400)
  • 400 ÷ 10=(40)
  • Think About It! If you REALLY love jellybeans, would you rather have 400 jellybeans OR 1/10 of 40,000 jellybeans? Why? (1/10 of 40,000 because that equals 4,000 jellybeans)
  • Sandy took 13,000 steps in one day. Mitchell took 1/10 of 130,000 steps in the same day. Who took more steps that day? (neither, they both took 13,000 steps)

Activity 2: Working With Decimals

Watch the video at the following web link to review some basic information about decimal numbers.
Web Link
Next, visit the following web link and follow these steps:
  1. Read the introduction and the information under "Place Value." Much of this information won't be new to you, but it provides a good review of how decimals fit into our place value system.
  2. When you get to the section that says, "Have a play with decimal numbers yourself," take time to click on the "x10" and "÷10" buttons multiple times in a row, and watch what happens to the number in the box above.
  3. Pay close attention to what happens to the decimal point and when and where zeros are added to the number.
Web Link
You're going to practice multiplying and dividing by 10 (finding 1/10 of a number) on the "Values Left and Right" sheet. Keep in mind that when you multiply by 10, numbers get greater, and when you divide by 10, numbers get smaller.
Student Activity Page
Now, your child will extend his understanding of how place values change moving left and right to working with decimal numbers to the hundredths. He will begin by watching a video about decimal numbers and then review decimals using an interactive online tool. As he works on this activity, he should keep in mind that when he multiplies by 10, numbers get greater, and when he divides by 10 (finds 1/10 of a number), numbers get smaller. He should also note how decimal points move when we multiply by 10 (point moves to the right) and divide by 10 (point moves to the left). He can use the website provided to review the basics of decimals and use the interactive tool to help him solve the problems on the activity page as needed.
"Values Left and Right" Answer Key