1 / 46

Rounding and Estimation Strategies for Accurate Computation

This text provides examples and practice problems for applying rounding and estimation strategies to solve mathematical problems. It covers rounding whole numbers and amounts of money, as well as estimating addition, subtraction, and multiplication problems with whole numbers up to 6 digits.

apriscilla
Download Presentation

Rounding and Estimation Strategies for Accurate Computation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. M4.A.3 Compute accurately and fluently and make reasonable estimates. M4.A.3.1 Apply rounding and/or estimation strategies to solve problems.

  2. M4.A.3.1 Eligible Content • M4.A.3.1.1 Round whole numbers to the nearest ten, hundred, thousand, ten-thousand or hundred-thousand • M4.A.3.1.2 Round amounts of money to the nearest dollar. • M4.A.3.1.3 Estimate the answer to addition, subtraction and multiplication problems using whole numbers through 6 digits (for multiplication, no more than 2 digits X 1 digit, excluding powers of 10).

  3. M4.A.3.1.1 Round whole numbers to the nearest ten, hundred, thousand, ten-thousand or hundred-thousand • M4.A.3.1.2 Round amounts of money to the nearest dollar.

  4. PSSA Sample Items

  5. Rounding

  6. Use rounding • When the question asks you • to estimate. • When the question asks • “about how many”…? • When an exact answer isn’t • possible. • When an answer is difficult to obtain.

  7. Memorize this Poem Find your number. Look right next door. 4 or less just ignore. 5 or more, add 1 more.

  8. Round this number to the nearestten thousand. Find your number. 3 6 8,9 7 1 Circle the number in the ten thousands place.

  9. Round this number to the nearestten thousand. Look right next door. 3 6 8,9 7 1 Draw an arrow to the right of the number.

  10. Round this number to the nearestten thousand. 4 or less, just ignore. 3 6 8,9 7 1 8 is larger than 4 so go to the next line of the poem.

  11. Round this number to the nearestten thousand. 5 or more, add 1 more. +1 3 6 8,9 7 1 Add 1 to the 6.

  12. Round this number to the nearestten thousand. 5 or more, add 1 more. 3 70,0 0 0 Add 1 to the 6 and all the numbers to the right of the 7 become 0’s.

  13. The Answer 368,971 rounded to the nearest ten thousand is 3 7 0,0 0 0

  14. Round this number to the nearestthousand. Find your number. 3 5, 3 2 7 Circle the number in the thousands place.

  15. Round this number to the nearestthousand. Look right next door. 3 5, 3 2 7 Draw an arrow to the right of the number.

  16. Round this number to the nearestthousand. 4 or less, just ignore. 3 5, 3 2 7 Since 3 is less than 4 we do not change the 5.

  17. Round this number to the nearestthousand. 4 or less, just ignore. 3 5, 0 0 0 Change the numbers to left of 5 to 0’s.

  18. The Answer 35,327 rounded to the nearest thousand is 3 5, 0 0 0

  19. Round this number to the nearestdollar. Find your number. $ 5. 87 Circle the number where the dollars are.

  20. Round this number to the nearestdollar. Look right next door. $ 5. 87 Draw an arrow to the right of the circled number.

  21. Round this number to the nearestdollar. 4 or less, just ignore. $ 5. 87 8 is greater than 4 so go to the next line of the poem.

  22. Round this number to the nearestdollar. 5 or more, add 1 more. +1 $ 5. 87 Since 8 is greater than 5 add 1 to the 5.

  23. Round this number to the nearestdollar. 5 or more, add 1 more. $ 6. 0 0 Change the 5 to a 6 and change all the numbers to the right to 0’s.

  24. The Answer $5.87 rounded to the nearest dollar is $ 6. 0 0

  25. Practice Rounding

  26. 478 696 233 713 485 778 452 305 841 500 700 200 700 500 800 500 300 800 Round to the Nearest Hundred

  27. 1,715 5,475 6,562 3,470 9,025 5,789 8,543 4,007 2,800 2,000 5,000 7,000 3,000 9,000 6,000 9,000 4,000 3,000 Round to the Nearest Thousand

  28. 48,253 61,744 54,769 35,535 48,600 70,209 15,437 49,036 68,703 50,000 60,000 50,000 40,000 50,000 70,000 20,000 50,000 70,000 Round to the Nearest Ten Thousand

  29. 516,573 430,001 112,786 807,921 576,439 156,748 856,125 239,875 186,093 500,000 400,000 100,000 800,000 600,000 200,000 900,000 200,000 200,000 Round to the Nearest Hundred Thousand

  30. Rounding Money Word Problems

  31. Mary bought two boxes of crackers for $0.99 each and a pound of grapes for $1.29. About how much did she spend? • About $3.00

  32. Martin has 4 quarters and 2 dimes. About how much money does he have? • $1.00

  33. At the taco stand, Jaleel bought a taco for $2.75 and a drink for $0.95. About how much did he spend? • $3.00

  34. M4.A.3.1.3 Estimate the answer to addition, subtraction and multiplication problems using whole numbers through 6 digits (for multiplication, no more than 2 digits X 1 digit, excluding powers of 10).

  35. PSSA Sample Item

  36. PSSA Sample Item

  37. PSSA Sample Item

  38. Estimating the Answer • Estimates are not exact numbers. To identify estimates, look for numbers that have been rounded, or look for clues such as almost, over, or about.

  39. Exact Numbers or Estimates?Example • Mount Rushmore National Memorial, the famous sculpture of 4 American presidents, was started in 1927. It was finished 14 years later and cost almost $1,000,000.00 to make! Mount Rushmore is over 5,500 ft. high. Each head is about 60 ft. tall. • In what year was the sculpture started? • How tall is each president’s head? • How many presidents are on Mount Rushmore?

  40. Refer to the paragraph about Mount Rushmore 4. Is the year 1927 an exact number or an estimate? How do you know? 5. Is it correct to say that the sculpture cost exactly $1,000,000.00 to make? Why or why not? 6. In what year was the sculpture completed? Is your answer an exact answer or an estimate? 7. Why is it important to know if numbers are exact or if they are estimates?

  41. Answer each question. Give a reason for your choice. Mount Rushmore National Memorial is off Highway 244 and is about 25 miles from Rapid City, South Dakota. The memorial is open 24 hours a day. Each year, more than 2,500,000 people come to view the sculpture. • Which number below is used as an estimate? • 2,500,000 visitors • Highway 244 • 24 hours a day

  42. 2. Which number below is used as an exact number? a. 2,500,000 visitors b. 25 miles c. 24 hours a day 3. How many miles is Mount Rushmore from Rapid City? a. exactly 25 miles b. about 25 miles c. 244 miles

  43. 32 + 27 = 52 – 37 = 86 – 43 = 763 – 214 = 3,564 + 758 = 7,638 + 3,879 = 2,375 + 4,680 = 24,316 + 13,452 = 47,865 + 26, 527 = 60 10 50 600 3,000 10,000 7,000 30,000 80,000 Estimate by rounding to the greatest place value

More Related