Lesson 5

News Number Line

Est. Class Sessions: 2

Developing the Lesson

Part 1. Represent Benchmarks on a Number Line

Create a Number Line.

Ask students:

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  • Count by 100,000s to 1 million. (one hundred thousand, two hundred thousand … )
  • How many 100,000s are in a million? (10)
  • If we decide a meter represents 100,000, how many meters do we need to represent one million? (10 meters)

Lay one meterstick along the top of the 10-meter paper strip for the number line. Use a red marker to mark each end of the meterstick on the adding machine tape. Label the left mark 0 and the right mark 100,000. Continue labeling the intervals 200,000; 300,000; and so on up to 1,000,000. Have students count along with you.

Tell students these numbers on the number line are called guides or benchmarks. See Figures 1 and 2 and Sample Dialog 1.

Ask:

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  • What other benchmarks would be helpful in placing a number such as 37,000 on the number line? (5000s, 1000s)
  • How can we divide each 100,000 to make it easier to place the numbers quickly on the number line? (ten 10,000s)
  • Let's look at our meterstick. How is the meterstick divided? (100 centimeters)
  • Does anyone have a suggestion for how we could divide up the 100 centimeters? (Possible responses: we could mark the 10s; we could mark 50 centimeters.)
  • If one whole meter is 100 centimeters and it represents 100,000 units, what will 50 centimeters represent? (50,000 units)
  • What will ten centimeters represent? (10,000 units)
  • Does anyone know what the name for ten centimeters is? (decimeter)
  • How many decimeters are in one meter? (ten decimeters)
  • How many 10,000s are in 100,000? (ten)
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Benchmark Numbers in the 10,000s

Teacher: We have measured out and marked in red benchmark numbers in the 100,000s. What other benchmarks would be helpful in placing a number such as 37,000 on the number line?

Jessie: I know that 37,000 would go somewhere between 0 and 100,000. I also know that halfway between 1 and 100,000 is 50,000.

Teacher: I think you're on to something! Let's think about this. We counted by 100,000s to get to 1,000,000. What might be an easy and convenient way to count from 0 to 100,000?

Nila: What about counting by 10,000s: 10,000; 20,000; 30,000 . . .100,000.

Teacher: That works well! Now take a look at your meterstick. Which numbers on your meterstick would correspond to 10,000; 20,000; etc?

Nila: That would be 10, 20, 30, etc.

Teacher: That's great! Grab a green pen. Place your meterstick above the number line and place a green mark at 10, 20, 30, etc. to stand for intervals of 10,000. (10,000; 20,000; 30,000 . . .)

Teacher: Do these additional benchmark numbers help us place 37,000 on our number line? How?

Jessie: That helps me a lot! I know 37,000 is greater than 30,000 but less than 40,000. I would place 37,000 between these two benchmark numbers, a little closer to 40,000 than 30,000 because 37,000 is closer to 40,000 than 30,000.

Teacher: You've got it!

Use a green marker to mark the intervals of 10,000 as students count, “zero, ten thousand, twenty thousand, thirty thousand … ninety thousand, and one hundred thousand.” Note 100,000 is already marked in red. Ask students to finish marking the 10,000 intervals from 100,000 to 1 million. (See Figure 2.)

If you use Option A or B for your number line, the completed number line should look similar to the one in Figure 3. In Part 2, students will use paper clips to attach each of the news number line index card strips from the Newswire display in the proper place along the number line.

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While some students finish marking the 10,000 intervals on the number line, have the rest of the class complete a DPP item.

If you use string for the number line, mark the benchmark 100,000 and 10,000 intervals with red and green markers, respectively. Attach red cards (100,000s benchmarks) and green cards (10,000s benchmarks) in their appropriate places. When students attach large numbers to the number line in Part 2, fold a portion of each index card strip from the Newswire display over to form a small flap. Fold the flap over the string and use a paper clip to attach the card to the number line. This should keep the index cards from slipping. See Figure 4.

Connect the Number Line to Big Base-Ten Pieces. Compare the number line to the big base-ten pieces the class created in Lesson 4. Be sure students can reference the Big Base-Ten Pieces they created. They can also refer to the picture of the pieces in Lesson 4 of their Student Guide. Remind students that a megabit (1,000,000) represents the largest number on the number line the class just created.

Ask:

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  • A megabit is 1,000,000 bits. Where on the number line is a super flat? (10,000)
  • How many super flats would it take to make a megabit? (10 super flats)
  • Can someone show us how to skip count by 100,000 on the number line? How many hops to 1,000,000? (0; 100,000; 200,000 … 1,000,000; 10 hops)
  • Where on the number line is a super skinny? (10,000)
  • How many super skinnies would it take to make a megabit? (100 super skinnies)
  • Can someone show us how to skip count by 10,000 on the number line? (0; 10,000; 20,000; 30,000; etc.)
  • How many 10,000 size hops are needed to reach 1,000,000? (100 hops)
  • Where on the number line is a pack or a super bit? (1000)
Student Guide:
Student Activity Book:
Master:
Number line marked by hundred thousands
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Number line marked by ten thousands
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Options A and B—number lines made with adding machine tape or 81/2 × 11-inch paper cut in half lengthwise
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Option C—number line made with string
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