1. Estimating Numbers Lesson 29

2. Math Vocabulary To “estimate” a # means: A close guess of the actual value, usually with some thought or calculation involved (based on “rounding”)

3. Two types of #s Strong Numbers: 5 6 7 8 9 *Have the strength to CHANGE a number (+1) Weak Numbers: 0 1 2 3 4 **Have no strength and keep numbers the same

4. Rounding Numbers Steps: 1) Identify # to estimate 2) Underline # to estimate 3) Circle # after 4) Determine strength of circled # 5) Estimate 6) Change ending #s to 0s Examples: Estimate 6143: 6143 ≈ 6000 Estimate 4952: 4952 ≈ 5000

5. Estimating Numbers Example: Estimate the sum of 3562 and 1234. 3562 + 1234 ≈ 4000 + 1000 5000 Example: Estimate the product of 58 and 194. 58 x 194 ≈ 60 x 200 12,000

6. Practice… a) Estimate 34,527. b) Estimate 567,982. c) Estimate the sum of 45,673 and 54,926. d) Estimate the difference of 826 and 275.