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REVIEW Copyright Ed2NetLearning, Inc2 Objectives Rounding the fractions to the nearest half or to a whole number Rounding the fractions to the nearest half or to a whole number Estimating sums and differences Estimating sums and differences Adding and subtractions with like denominators Adding and subtractions with like denominators Adding and subtracting fractions with unlike denominators Adding and subtracting fractions with unlike denominators Adding and subtracting mixed numbers Adding and subtracting mixed numbers Subtracting mixed numbers with renaming Subtracting mixed numbers with renaming

REVIEW Copyright Ed2NetLearning, Inc3 Rounding Fractions & Mixed Numbers Round Up: If the numerator is almost as large as the denominator, round the number up to the next whole number. Round Up: If the numerator is almost as large as the denominator, round the number up to the next whole number. Round to ½ : If the numerator is about half of the denominator, round the fraction to ½. Round to ½ : If the numerator is about half of the denominator, round the fraction to ½. Round down: If the numerator is much smaller than the denominator, round the number down to the whole number. Round down: If the numerator is much smaller than the denominator, round the number down to the whole number.

REVIEW Copyright Ed2NetLearning, Inc4 Examples Round the numbers: 1. 5/6= 1, since 5 is almost large as /3 = ½, since 1 is about half of /9= 0, since 2 is much smaller than 9.

REVIEW Copyright Ed2NetLearning, Inc5 Assignments Round each number : Round each number : 1. 4/ / / / /9

REVIEW Copyright Ed2NetLearning, Inc6 Estimating Sums and Differences We can estimate sums and differences by rounding each fraction to the nearest half. Then add or subtract. We can estimate sums and differences by rounding each fraction to the nearest half. Then add or subtract. We can estimate sums and differences of mixed numbers by rounding each number to the nearest whole number. We can estimate sums and differences of mixed numbers by rounding each number to the nearest whole number.

REVIEW Copyright Ed2NetLearning, Inc7 Examples 1. Estimate 7/8 + 11/12 7/8 rounds to 1 ; 11/12 rounds to 1 7/8 + 11/12 = = 2 2. Estimate 5/12 – 1/6 5/12 rounds to ½ ; 1/6 rounds to 0 5/12 – 1/6 = ½ - 0 = ½

REVIEW Copyright Ed2NetLearning, Inc8 Practice Problems Estimate Estimate 1. ¾ + ½ 2. 7/8 – ¼ 3. 5/6 – 4/9 4. 9/10 + 8/ /14 – 7/16

REVIEW Copyright Ed2NetLearning, Inc9 Mixed Number Sum and Difference Estimate 4 5/ /5 Estimate 4 5/ /5 4 5/6 rounds to = 5 and 2 1/5 rounds to = 2 4 5/ /5 = = 7 2. Estimate 3 2/3 – 1 7/8 3 2/3 rounds to 4 and 1 7/8 rounds to 2 3 2/3 – 1 7/8 = 4 – 2 = 2 3 2/3 – 1 7/8 = 4 – 2 = 2

REVIEW Copyright Ed2NetLearning, Inc10 Practice Problems Estimate /9 – 1 6/ /8 – 2 4/ /12 – 2 ¼ 4. 1/ / / /9

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REVIEW Copyright Ed2NetLearning, Inc12 Adding and Subtracting Fractions with Like Denominators To add fractions with the same denominators, add the numerators. Use the same denominator in the sum. To add fractions with the same denominators, add the numerators. Use the same denominator in the sum. To subtract fractions with the same denominators, subtract the numerators. Use the same denominator in the difference. To subtract fractions with the same denominators, subtract the numerators. Use the same denominator in the difference.

REVIEW Copyright Ed2NetLearning, Inc13 Examples Add or Subtract: Write in the simplest form 1. 5/12 + 6/12 = (5 + 6)/12 = 11/ /12 – 3/12 = (11 – 3)/12 = 8/12 = 2/3 3. 6/7 – 4/7=2/7 4. ¾ + ¼= 4/4=1

REVIEW Copyright Ed2NetLearning, Inc14 Practice Problems Add or Subtract. Write in simplest form. 1. 3/8 + 1/8 2. 2/9 + 4/9 3. 3/10 – 1/ /9 + 2/9 5. 5/6 + 5/6 6. 3/10 – 1/ /11 – 5/11

REVIEW Copyright Ed2NetLearning, Inc15 Word Problems Terrance ate 4/12 of a large pizza, and Sam ate 5/12. how much of the pizza did they eat in all ? Terrance ate 4/12 of a large pizza, and Sam ate 5/12. how much of the pizza did they eat in all ? 4/12 + 5/12 = 9/12 = ¾ 4/12 + 5/12 = 9/12 = ¾ About 3/10 of the Earth’s surface is land. The rest is covered by water. How much of the earth is covered by water? About 3/10 of the Earth’s surface is land. The rest is covered by water. How much of the earth is covered by water? 1 – 3/10 =10/10 – 3/10 = 7/10. 1 – 3/10 =10/10 – 3/10 = 7/10.

REVIEW Copyright Ed2NetLearning, Inc16 Now your turn A recipe calls for 2/3 cup of water, 1/3 cup oil, and 1/3 cup milk. How much liquid is used in the recipe? A recipe calls for 2/3 cup of water, 1/3 cup oil, and 1/3 cup milk. How much liquid is used in the recipe? Total rainfall for the whole week was 7/12 inch. The rainfall for Wednesday through Monday was 3/12. how much rain fell on Sunday? Total rainfall for the whole week was 7/12 inch. The rainfall for Wednesday through Monday was 3/12. how much rain fell on Sunday?

REVIEW Copyright Ed2NetLearning, Inc17 Adding and Subtracting Fractions with Unlike Denominators To find the sum or difference of two fractions with unlike denominators, rename the fractions using the least common denominator (LCD). Then add or subtract and simplify. To find the sum or difference of two fractions with unlike denominators, rename the fractions using the least common denominator (LCD). Then add or subtract and simplify.

REVIEW Copyright Ed2NetLearning, Inc18 Examples Add or Subtract. Write in simplest form. Add or Subtract. Write in simplest form. 1. ½ + 2/3 LCD of 2 and 3 = 6 ½ = 1 x 3 = 3 ; 2/3 = 2 x 2 = 4 2 x x x x 2 6 ½ + 2/3 = 3/6 + 4/6 = 7/6 = 1 1/6. ½ + 2/3 = 3/6 + 4/6 = 7/6 = 1 1/ /9 – 1/6 LCD of 9 and 6 = 18 7/9 = 7 x 2 = 14 ; 1/6 = 1 x 3 = 3 9 x x x x /9 – 1/6 = 14/18 – 3/18 = 11/18.

REVIEW Copyright Ed2NetLearning, Inc19 PRACTICE PROBLEMS Add or Subtract. Write in simplest form. 1. 5/8 + ¼ 2. 7/9 – 1/12 3. ¾ + 5/6 4. 9/10 – ¼ 5. 4/5 + 2/10

REVIEW Copyright Ed2NetLearning, Inc20 Let’s solve this puzzle. // jigsaw-puzzles/12-piece-jigsaw/ coloredblocks.html // jigsaw-puzzles/12-piece-jigsaw/ coloredblocks.html // jigsaw-puzzles/12-piece-jigsaw/ coloredblocks.html // jigsaw-puzzles/12-piece-jigsaw/ coloredblocks.html

REVIEW Copyright Ed2NetLearning, Inc21 Adding and Subtracting Mixed Numbers To add or subtract mixed numbers, first add or subtract the fractions. Then add or subtract the whole numbers. Rename and simplify if necessary. To add or subtract mixed numbers, first add or subtract the fractions. Then add or subtract the whole numbers. Rename and simplify if necessary.

REVIEW Copyright Ed2NetLearning, Inc22 Examples Find 5 3/8 – 3 1/3 Find 5 3/8 – 3 1/3 3/8 – 1/3 = 9/24 – 8/24 = 1/24 5 – 3 = 2 5 3/8 – 3 1/3 = 2 1/24 Find 3 2/ /5 2/5 + 3/5 = 5/5 = = 5

REVIEW Copyright Ed2NetLearning, Inc23 Exercises Add or Subtract Add or Subtract /10 – 3 2/5 2. 2¾ + 1 1/ /9 – 1 1/ / / /7 – 2 5/14

REVIEW Copyright Ed2NetLearning, Inc24 Assignments During the weekend, Brown spent 1 ¾ hour on playing football and 2 1/6 hours for playing chess. How much time did he spend in all subjects? During the weekend, Brown spent 1 ¾ hour on playing football and 2 1/6 hours for playing chess. How much time did he spend in all subjects?

REVIEW Copyright Ed2NetLearning, Inc25 Subtracting Mixed numbers with renaming Find 5 – 2 2/3 Find 5 – 2 2/3 5 = 4 3/3 5 – 2 2/3 = 4 3/3 – 2 2/3 = 2 1/3 = 2 1/3 Find 4 3/8 – 2 5/8 = 4 11/8 – 2 5/8 = 2 6/8 = 2 ¾ = 2 6/8 = 2 ¾ Find 23 1/6 – 11 1/3 = 22 7/6 – 11 2/6 = 11 5/6 = 11 5/6

REVIEW Copyright Ed2NetLearning, Inc26 Practice Problems 1. 5 – 3 2/ /6 – 4 5/ /7 – 1 2/ /8 – 1 ¾ /5 – 9 2/3

REVIEW Copyright Ed2NetLearning, Inc27 Assignments A board measures 9 1/3 feet. A piece measuring 5 5/8 feet is cut off. Find the length of the remaining board? A board measures 9 1/3 feet. A piece measuring 5 5/8 feet is cut off. Find the length of the remaining board?

REVIEW Copyright Ed2NetLearning, Inc28 That ‘s all for today. See you next time That ‘s all for today. See you next time