Estimating Sums and Differences of Whole Numbers

You know how to round numbers. Today, you will use rounding to estimate sums and differences.

• What are some things that are often rounded?

Vera went on a 3 day trip in which she traveled 336 miles on the first

day, 423 on the second day, and 357 miles on the third day. Is 300 or 400 a more reasonable estimate for about

how far she went on each of the 3 days?

What is each number rounded to the nearest hundred?

What is the sum of the rounded numbers?

Estimate 518+271 by rounding to the nearest hundred.

• Then, estimate the sum by rounding to the nearest ten.

• Which estimate is closer to the exact sum?

Round each number to the nearest hundred:

• 1,250 --

• +204--

• _________

• Then round to the nearest ten! Which estimate is closer!?

Please work on pages 94-95 # 1-30. You must show your estimated numbers before adding!!!

• Go over work.

• Castle learning/Problem Solving