Mental Math Estimate Sums and Differences

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

Round to the nearest hundred, then estimate the difference:

642 − 137

• 600

• 780

• 500

• 510

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

47,623 - 12,385 =

• 40

• 34,238

• 40,000

• 30,000

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

887,167 - 342,208 =

• 500,000

• 554,000

• 545,959

• 550,000

Round to the nearest thousand, then estimate the difference:

98,412 - 45,802

• 53,000

• 51,000

• 52,000

• 51,872