Teachers, save “Estimate and Add - Three-Digit Numbers” to assign it to your class.

For each problem... 1. Round each addend to the nearest TEN and add the estimated sums. 2. Round each addend to the nearest HUNDRED and add the estimated sums. 3. Add the exact sums. 4. Which estimate was closest to the exact sum? Circle your answer. (Bonus: Record why you think that estimate was closer.) There are 5 pages to this activity.