Reference home Curriculum 3A Chapter 1 Lesson 7

3A · Chapter 1 · Lesson 07

Rounding to the Nearest Thousand

Find the two bounding multiples of 1,000., Decide the nearest thousand by the midpoint., Explain and apply the usual half-up convention for positive whole numbers.

MATH-3A-C01-L07About 40 minutes, flexible

Your starting challenge

Is 6,499 closer to 6,000 or 7,000? What happens if we add only 1?

By the end, you can…

  • Find the two bounding multiples of 1,000.
  • Decide the nearest thousand by the midpoint.
  • Explain and apply the usual half-up convention for positive whole numbers.

Before starting, you should know…

  • Read number lines and compare four-digit numbers.

Entry · 2 questions

Quick prerequisite check

Try these two before the lesson. If either is confusing, review the listed prerequisites first.

  1. E1 A number line runs from 5,000 to 7,000 in 2 equal intervals. What is the step per interval?
    Show answer and reasoning

    Answer: 1,000

    The total distance is 2,000. Divide by 2 equal intervals: 1,000.

    If your answer differs — Ticks versus spaces: Count INTERVALS, not tick marks. Find total distance, divide by interval count, and label each tick. Review this concept.
  2. E2 Insert <, >, or =: 6,501 ___ 6,500.
    Show answer and reasoning

    Answer: >

    Compare digits from the highest place that differs. 6,501 > 6,500.

    If your answer differs — Rightmost-digit trap: Compare from the LEFTMOST unequal place. One larger place outweighs all smaller places together. Review this concept.

Vocabulary to know

roundingReplacing a number with a nearby number at a specified place.
nearest thousandThe multiple of 1,000 closest to a number.
midpointThe halfway value between two bounding multiples.
estimateAn approximate value used when an exact value is unnecessary.

Learn the concept

Find the bounds

For 6,499 the surrounding thousands are 6,000 and 7,000. Their midpoint is 6,500. Since 6,499 is below the midpoint, it rounds to 6,000.

How to handle halfway values

For positive whole numbers, we use the common classroom convention: exactly halfway rounds up. Thus 6,500 rounds to 7,000.

An estimate is not an exact measurement

Rounding supports mental calculation and reasonableness checks. Report an original exact quantity when a problem requires it; do not silently replace an exact answer with a rounded one.

6,0007,0006,499midpoint: 6,500
6,499 is just below the midpoint of 6,500, so it rounds down.

Work through examples

Study the explanation; then try each check before opening its answer.

Worked example 1

Round below the midpoint

Round 6,499 to the nearest thousand.

  1. Bounds are 6,000 and 7,000.
  2. Halfway is 6,500.
  3. 6,499 is less than halfway.

Result: 6,000

Now you try · Understanding check 1

Round 6,501 to the nearest thousand.
Reveal answer and explanation

7,000 — It lies between 6,000 and 7,000; the midpoint is 6,500. With halfway values rounded up, choose 7,000.

If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.

Worked example 2

A halfway case

Round 3,500 to the nearest thousand.

  1. 3,500 is exactly halfway between 3,000 and 4,000.
  2. With the usual positive-number half-up rule, choose the upper thousand.

Result: 4,000

Now you try · Understanding check 2

Round 8,500 to the nearest thousand.
Reveal answer and explanation

9,000 — It lies between 8,000 and 9,000; the midpoint is 8,500. With halfway values rounded up, choose 9,000.

If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.

Worked example 3

Round across the digit boundary

Round 9,620 to the nearest thousand.

  1. Surrounding thousands are 9,000 and 10,000.
  2. Midpoint is 9,500, and 9,620 is above it.

Result: 10,000

Now you try · Understanding check 3

Round 9,499 to the nearest thousand.
Reveal answer and explanation

9,000 — It lies between 9,000 and 10,000; the midpoint is 9,500. With halfway values rounded up, choose 9,000.

If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.

Guided · 4 questions

Guided practice

Try each problem; return to a visual model if you need one.

  1. G1 Round 2,499 to the nearest thousand.
    Show answer and reasoning

    Answer: 2,000

    It lies between 2,000 and 3,000; the midpoint is 2,500. With halfway values rounded up, choose 2,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  2. G2 Round 2,500 to the nearest thousand.
    Show answer and reasoning

    Answer: 3,000

    It lies between 2,000 and 3,000; the midpoint is 2,500. With halfway values rounded up, choose 3,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  3. G3 Round 8,299 to the nearest thousand.
    Show answer and reasoning

    Answer: 8,000

    It lies between 8,000 and 9,000; the midpoint is 8,500. With halfway values rounded up, choose 8,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  4. G4 Round 9,700 to the nearest thousand.
    Show answer and reasoning

    Answer: 10,000

    It lies between 9,000 and 10,000; the midpoint is 9,500. With halfway values rounded up, choose 10,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.

Independent · 8 questions

Independent practice

Work without looking at examples first. Show your thinking on paper.

  1. I1 Round 1,480 to the nearest thousand.
    Show answer and reasoning

    Answer: 1,000

    It lies between 1,000 and 2,000; the midpoint is 1,500. With halfway values rounded up, choose 1,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  2. I2 Round 1,500 to the nearest thousand.
    Show answer and reasoning

    Answer: 2,000

    It lies between 1,000 and 2,000; the midpoint is 1,500. With halfway values rounded up, choose 2,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  3. I3 Round 4,512 to the nearest thousand.
    Show answer and reasoning

    Answer: 5,000

    It lies between 4,000 and 5,000; the midpoint is 4,500. With halfway values rounded up, choose 5,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  4. I4 Round 7,501 to the nearest thousand.
    Show answer and reasoning

    Answer: 8,000

    It lies between 7,000 and 8,000; the midpoint is 7,500. With halfway values rounded up, choose 8,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  5. I5 Round 6,999 to the nearest thousand.
    Show answer and reasoning

    Answer: 7,000

    It lies between 6,000 and 7,000; the midpoint is 6,500. With halfway values rounded up, choose 7,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  6. I6 Round 8,499 to the nearest thousand.
    Show answer and reasoning

    Answer: 8,000

    It lies between 8,000 and 9,000; the midpoint is 8,500. With halfway values rounded up, choose 8,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  7. I7 Round 9,999 to the nearest thousand.
    Show answer and reasoning

    Answer: 10,000

    It lies between 9,000 and 10,000; the midpoint is 9,500. With halfway values rounded up, choose 10,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  8. I8 Round 5,000 to the nearest thousand.
    Show answer and reasoning

    Answer: 5,000

    5,000 is already an exact multiple of 1,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.

Challenge · 2 questions

Challenge and transfer

These nonroutine problems require you to explain or adapt what you learned.

  1. C1 A whole number rounds to 6,000 to the nearest thousand. What is the smallest whole number it could have been?
    Show answer and reasoning

    Answer: 5,500

    The interval of whole numbers rounding to 6,000 starts halfway below, at 5,500, and ends at 6,499 (with halfway values rounded up).

    If your answer differs — Repeated rounding: Return to the ORIGINAL number for each target place. Draw each requested pair of bounds and its midpoint separately. Review this concept.
  2. C2 What is the greatest whole number below 10,000 that rounds to 9,000 to the nearest thousand?
    Show answer and reasoning

    Answer: 9,499

    9,500 rounds to 10,000, so the largest whole number still rounding to 9,000 is 9,499.

    If your answer differs — Repeated rounding: Return to the ORIGINAL number for each target place. Draw each requested pair of bounds and its midpoint separately. Review this concept.

Exit · 3 questions

Exit check

Use these fresh problems to decide whether to proceed. Answers should be independent.

  1. E1 Round 3,499 to the nearest thousand.
    Show answer and reasoning

    Answer: 3,000

    It lies between 3,000 and 4,000; the midpoint is 3,500. With halfway values rounded up, choose 3,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  2. E2 Round 3,500 to the nearest thousand.
    Show answer and reasoning

    Answer: 4,000

    It lies between 3,000 and 4,000; the midpoint is 3,500. With halfway values rounded up, choose 4,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
  3. E3 What is the midpoint between 8,000 and 9,000?
    Show answer and reasoning

    Answer: 8,500

    Half the 1,000 gap is 500; add to 8,000.

    If your answer differs — Wrong midpoint: Locate the two neighboring thousands. Compare the original number with the halfway thousand (500 more). Review this concept.
Mastery note: A correct answer matters, but so does explaining why. If you missed an important idea, revisit the model and try similar problems on a different day. For full solutions, ask a parent or tutor to consult the separate answer-key copy.
Next lesson: Rounding to the Nearest Hundred →