1. Rounding Numbers
Lesson 1.9

2. Math Vocabulary
To “round” a # means: To use the “strength” of numbers to change or keep another number’s value, so that the entire number is not exact but close to the original

3. Strong Numbers: 5 6 7 8 9 *Have the strength to CHANGE a number (+1)
Two types of #s
Strong Numbers: *Have the strength to CHANGE a number (+1)
Weak Numbers: **Have no strength and keep numbers the same

4. Rounding Numbers Examples: 283 ≈ 300 Round 283 to nearest ten: 283≈
Round 283 to nearest hundred:
283 ≈
300
Round 283 to nearest ten:
283≈
280
Steps:
Identify # to be rounded
Underline # to be rounded
Circle # AFTER underlined #
Determine if circled # is strong or weak…
Round
Change remaining #s AFTER to 0s.

5. Rounding Numbers Step Summary: Identify Underline Circle
Determine strength
ROUND
Change leftovers to 0s
Examples:
Round 39,567,000 to nearest million:
39,567,000 ≈
40,000,000
Round 4,367,633 to nearest thousand:
4,367,633 ≈
4,368,000

6. Practice… Round 1760 to the nearest hundred.
Round 5489 to the nearest thousand.
Round 186,282 to the nearest ten thousand.