1. © 2007 M. Tallman

2. Find your number. Look right next door. 27 Step 1: Circle the digit in the place that you must round to. Step 2: Draw an arrow to the place on the right. Round to the nearest thousands place., 8 6

3. Step 1: Circle the digit in the place that you must round to. Step 2: Draw an arrow to the place on the right. Step 3: If the number is four or less, then the circled number stays the same. Step 4: All numbers to the right of the circled number become zeros. 000 2 8 6 4 or less, just ignore. 2 is less than 4 Just Ignore! 7, Round to the nearest thousands place.

4. © 2007 M. Tallman 9 Find your number. Round to the nearest hundreds place. Look right next door. Step 1: Circle the digit in the place that you must round to. Step 2: Draw an arrow to the place on the right. 71, 2

5. © 2007 M. Tallman Step 1: Circle the digit in the place that you must round to. Step 2: Draw an arrow to the place on the right. Step 3: If the number is four or less, then the circled number stays the same. Step 4: If the number is 5 or greater, then add 1 to the circled number. Step 5: All numbers to the right of the circled number become zeros. 9 27 0 0 8 4 or less, just ignore. 5 or more, add 1 more. 9 is not less than 4 Round to the nearest hundreds place. 7 + 1 = 8 1,

6. © 2007 M. Tallman When to use estimation… WWhen an exact answer is not needed. WWhen you need to compute a problem quickly. TTo check your work.

7. 496 - 112 500 100 - = 400 Step 1: Rounding is always first. Decide which place to round to. Step 2: Round each number to the hundreds place. Step 3: Now you can subtract 100 from 500, mentally. The actual answer is 384, so our estimation is pretty accurate.

8. © 2007 M. Tallman 5,251 - 896 5,000 900- = 4,100 Step 1: Rounding is always first. Decide which place to round to. Step 2: Round the first addend to the thousands place and the second addend to the hundreds place. Step 3: Now you can subtract 900 from 5,000, mentally. The actual answer is 4,355, so our estimation is pretty accurate Rounding Tip: The lower the place, the more accurate the answer. However, if you round too low, your problem may be more difficult to solve. Rounding Tip: The higher the place, the easier your problem will be to solve. However, your answer may not be as accurate.

9. © 2007 M. Tallman 52,187 - 18,978 50,000 20,000 - = 30,000 Step 1: Rounding is always first. Decide which place to round to. Step 2: Round each addend to the ten thousands place. Step 3: Now you can subtract 20,000 from 50,000, mentally. The actual answer is 33,209, so our estimation is pretty accurate.

10. © 2007 M. Tallman $19.67 - $6.35 $20.00 $6.00 - = $14.00 Step 1: Rounding is always first. Decide which place to round to. Step 2: Round $19.67 to the nearest ten dollars. Round $6.35 to the nearest dollar. Step 3: Now you can subtract $6.00 from $20.00, mentally. The actual answer is $13.32, so our estimation is pretty accurate.

11. © 2007 M. Tallman 1. $21.89 - $6.78 5,000 200 700- 500 = 300 - 200 = $13.00 4. 4,897 - 898 3. 745 - 467 Estimate Each Difference 2. 467 - 221 $20.00 - $7.00 = 4,100 - 900 =

12. © 2007 M. Tallman 5. 897,965 - 12,854 800,000 2,000 6,000- 4,000 = $20.00 $50.00 - $30.00 = 890,000 8. 765,987 - 46,980 7. 5,897 - 4,465 Estimate Each Difference 6. $47.90 - $27.87 900,000 - 10,000 = 750,000 - 50,000 =

13. © 2007 M. Tallman 9. $8.75 - $3.98 700,000 5,000 8,000- 3,000 = $200.00 $700.00 - $500.00 = $5.00 12. 667,876 - 446,987 11. 8,321 - 3,432 Estimate Each Difference 10. $776.98 - $547.98 $9.00 - $4.00 = 300,000 - 400,000 =