Estimating Sums and Differences by Rounding

237 fifth graders and 346 fourth graders went on a field trip. Estimate how many more fourth graders were on a field trip than fifth graders.

• 200 more
• 109 more
• 100 more
• 110 more

If you have 382, you might say you have ABOUT...

• 400
• 390
• 450
• 350

If you have 819, you might say you have approximately...

• 900
• 880
• 820
• 810

Mrs. Krutak used 1,820 pencils last year. This year she thinks she will use 1,932 pencils. About how many pencils is that all together?

• 3,000.
• 3,700.
• 4,000.
• 3,752.

Round to the nearest hundred, then estimate the sum:

123 + 456

• 580

• 600

• 650

• 500

Round to the nearest thousand, then estimate the sum:

2,764 + 4,851

• 7,000

• 6,000

• 5,000

• 8,000

Round to the nearest ten thousand, then estimate the sum:

315,245 + 41,559

• 360,000

• 350,000

• 357,000

• 340,000

Round to the nearest thousand, then estimate the sum:

25,219 + 4,876

• 29,000

• 31,000

• 30,000

• 35,000

Round to the nearest thousand, then estimate the sum:

66,246 + 22,651

• 89,000

• 88,000

• 90,000

• 89,748

Round to the nearest ten thousand, then estimate the sum.

65,447 + 124,557

• 80,000

• 170,000

• 180,000

• 190,000