1. Section 3.1 Rounding and Estimating
Algebra Concepts
Section 3.1
Rounding and Estimating

2. What does the word estimate mean?

3. In math, sometimes we estimate the answer.
We don’t always need an EXACT answer.
How much will
the repair bill
be?

4. Know place values.

5. Know decimal places.

6. What is the distance from Earth to Mars?
62.6 million miles
Is this an approximate answer?

7. This little baby weighs 13 pounds 10 ounces.
How is this different from your weight if you go to the doctor’s office?

10. Round to the underlined place
#1 3,564,389 # # #4 13,540,599

12. Estimate the sum or difference by rounding
#1 $36.78−$ −4≈$33 # − −12≈14 #3 $468+$ ≈$900

13. Front end estimation
#1 Add the numbers in the largest place value column
#2 Estimate the sum of the remaining places by rounding
#3 Combine the first sum with the second sum

14. Estimate using front-end estimation.
# =8 (thousands place)
# =1000
#3 8, ≈9000
Actual answer

15. Estimate using front-end estimating
#1 $ $12.10 # #

16. Estimate by clustering- find an approximate average of all the numbers added and multiply that number by how many numbers are added
$2.97+$3.29+$2.86+$3.11
About $3.00
4($3.00)≈$12.00

17. Estimate by clustering
# # #

18. You can pick your favorite method for estimating- your answers are just that- an estimate!