Unit 1 6 in Jay found the volume of the prism pictured to the right by multiplying 5 × 6 and then adding: 30 + 30 + 30 = 90. He says the volume is 90 cubic inches. 5 in 3 in Step A: Maria says he did it wrong. He should have multiplied the bottom first (3 × 5) and then multiplied by the height. Explain to Maria why Jay’s method works and is equivalent to her method. Possible explanation: Jay thought about this problem as layers. He calculated the area of the side (5 x 6) and imagined there were three of them, so he added them up. 3 x 5 x 6= 90 as well. Step B: Use Jay’s method to find the volume of this right rectangular prism. 5 ft 5 x 3 = 15 2 ft 3 ft Wicomico County Board of Education 15 + 15 = 30 cubic feet 2014-2015 Grade 5 2 Unit 1 The following structure is composed of two right rectangular prisms that each measure 12 inches by 10 inches by 5 inches, and one right rectangular prism that measures 10 inches by 8 inches by 36 inches. What is the total volume of the structure? Explain your thinking. Wicomico County Board of Education 2014-2015 Grade 5 3 Unit 1 Juliet wants to know if the chicken broth in this beaker will fit into this rectangular food storage container. Explain how you would figure it out without pouring the contents in. If it will fit, how much more broth could the storage container hold? If it will not fit, how much broth would be left over? (Remember 1 cm3 = 1 mL.) 4L 15 cm 2L 7 cm 20 cm Wicomico County Board of Education 2014-2015 Grade 5 4 Unit 1 An aquarium is in the shape of a rectangular prism. The base of the aquarium has an area of 40 square inches. When 160 cubic inches of water is poured into the aquarium, the water level is 2 inches from the top of the container. Step A: What is the volume of the aquarium? Show your work. 240 200 160 120 0 80 40 Step B: Marty said the dimension of the aquarium must be 8 x 5 x 6 in. However, Jackson said the dimension of the aquarium were 10 x 4 x 6 in Who is correct? Explain how you know. Both Marty and Jackson could be correct. Marty: 8 x 5 = 40 sq in. This would be the area of the base, and 40 x 6 = 240 cubic inches would be the volume. Jackson: 10 x 4 = 40 sq in. This would be the area of the base, and 40 x 6 = 240 cubic inches would be the volume. Wicomico County Board of Education 2014-2015 Grade 5 5 Unit 1 Cari is the lead architect for the city’s new aquarium. All of the tanks in the aquarium will be rectangular prisms where the side lengths are whole numbers. Cari knows that a certain species of fish needs at least 240 cubic feet of water in their tank. Create 3 separate tanks that hold exactly 240 cubic feet of water. In the back of the aquarium, Cari realizes that the ceiling is only 10 feet high. She needs to create a tank that can hold exactly 100 cubic feet of water. Name one way that she could build a tank that is not taller than 10 feet. There are many possible solutions to this task. Here are several possible answers: Length Width Height 8 ft 6 ft 5 ft 10 ft 8 ft 3 ft 10 ft 6 ft 4 ft 12 ft 5 ft 4 ft 15 ft 4 ft 4 ft The teacher should prompt students to think about what their tank would look like in real-life. A tank that is 40 feet long, 3 feet wide and 2 feet high would be very long, skinny and short. This tank would not be good for bigger fish, but it could be useful to watch something small that does not need a lot of space to move, such as a turtle. There are many possible solutions to this task. Here are several possible answers: Length 5 ft 2 ft 10 ft 25 ft 25ft Wicomico County Board of Education Width 5ft 10 ft 1 ft 2 ft 4 ft Height 4 ft 5 ft 10 ft 2 ft 1 ft 2014-2015 Grade 5 6 Unit 1 A local home improvement store sold mulch. The store had a large container to hold the mulch that was 20 yards long, 12 yards wide and 8 yards tall. The store manager filled the container with bags that each contained 12 cubic yards of mulch. How many bags of mulch will it take to fill the container? ________ bags 8 yards 12 yards 20 yards The volume of the box is 12 x 8 x 20 = 1,920 cubic yards. 1,920 ÷ 12 = 160. So 160 bags of mulch will fill the container. Wicomico County Board of Education 2014-2015 Grade 5 7 Unit 1 Using the digits 2,8,6,3 figure out the arrangement of the digits which gives you the greatest and least product. Greatest Product: x 8 2 6 3 82 X 63 6 160 180 4800 5146 5,166 38 X 26 48 180 160 600 988 Least Product: x 3 8 2 6 988 Wicomico County Board of Education 2014-2015 Grade 5 8 Unit 1 Draw a visual model to solve this problem: Jasmine was helping her mother color eggs for a party. She carefully placed 41 eggs into egg cartons. Each carton held 12 eggs. How many cartons would she need for the eggs? ____________ 4 cartons Find all the numbers that divide 100 with a remainder of 4. What is the largest two-digit divisor that can divide 100 and still have a remainder of 4? Use base ten blocks to model this problem. Students should realize they are finding numbers which divide into 96 evenly. However not all of the factors of 96 will work for this problem. For example 96 is divisible by 2, but when dividing 100 by 2 will not result in a remainder of 4. 6, 8, 12, 16, 24, 32, 48, 96 all divide 100 and have a remainder 4. 96 is the largest. Wicomico County Board of Education 2014-2015 Grade 5 9 Unit 1 Draw a visual model to solve this problem. The art teacher has 384 paintbrushes for his classroom. He is organizing his closet and plans to buy plastic boxes for the paintbrushes. He places 16 paintbrushes in each box. How many boxes will he need? _________ The art teacher will need 24 plastic boxes. Wicomico County Board of Education 2014-2015 Grade 5 10 Unit 1 Generate and solve another division problem with the same quotient and remainder as the two problems below. Explain your strategy for creating the new problem. 3 1 7 6 3 5 1 1 2 3 4 2 1 3 8 1 2 6 1 2 The student should generate a division problem with a quotient of 3 and remainder of 12 and uses a sound strategy (e.g., writes a checking equation ____ = 3 x_____+ 12). For example: Wicomico County Board of Education 2014-2015 Grade 5 11 Unit 2 A baker uses 5.5 lb of flour daily. Step A: How many ounces of flour will he use in two weeks? Use words, numbers, and pictures to explain your thinking. (1 lb = 16 oz) Step B: The baker’s recipe for a loaf of bread calls for 12 oz of flour. If he uses all of his flour to make loaves of bread, how many full loaves can he bake in two weeks? 12 1232 100 -1200 102 R 8 The baker can bake 102 full loaves in two weeks. 32 -24 2 8 Wicomico County Board of Education 2014-2015 Grade 5 12 Unit 2 Step C: The baker sends all his bread to one store. If he can pack up to 15 loaves of bread in a box for shipping, what is the minimum number of boxes required to ship all the loaves baked in two weeks. Explain your reasoning. 15 102 6 The baker will need 7 boxes to ship all the bread. The last box won’t be full. It will have 12 loaves in it. -90 12 Step D: The baker pays $0.80 per pound for sugar and $1.25 per pound for butter. Write an expression that shows how much the baker will spend if he buys 6 pounds of butter and 20 pounds of sugar. (6 x $1.25) + (20 x $0.80) Step E: Chocolate sprinkles cost 1/10 as much per pound as sugar. Find the baker’s total cost for 100 pounds of chocolate sprinkles. Explain the number of zeros and the placement of the decimal in your answer using a place value chart. Wicomico County Board of Education 2014-2015 Grade 5 13 Unit 2 Model the number 8.88 on the place value chart. Step A: Use words, numbers, and your model to explain why each of the digits has a different value. Be sure to use “ten times as much” and “one tenth of” in your explanation. Step B: Multiply 8.88 x 104. Explain the shift of the digits, the change in the value of each digit, and the number of zeroes in the product. Wicomico County Board of Education 2014-2015 Grade 5 14 Unit 2 Step C: Divide the product from (b) by 102. Explain the shift of the digits and how the value of each digit changed. Unit 2 Rainfall collected in a rain gauge was found to be 2.3 cm when rounded to the nearest tenth of a centimeter. Step A: Circle all the measurements below that could be the actual measurement of the rainfall. 2.251 cm 2.349 cm 2.352 cm 2.295 cm Step B: Convert the rounded measurement to meters. Write an equation to show your work. 2.3 cm ÷ 102 = 0.023m or 2.3 ÷100 = 0.023 Wicomico County Board of Education 2014-2015 Grade 5 15 Unit 2 Express the missing divisor using a power of 10. Explain your reasoning using a place value model. a. 5.2 ÷ _____ = 0.052 b. 7,650 ÷ _______ = 7.65 The student should express the divisors as powers of 10 either as multiples of 10 or exponents and shows correct reasoning on a place value chart for both Part (a) and Part (b). a. 100 or 102 or both Wicomico County Board of Education b. 1000 or 103 or both 2014-2015 Grade 5 16 Unit 2 Show three equivalent forms for the number seventy-two hundredths. Possible solutions: 0.72 72/100 720/1000 70/100 + 2/100 7/10 + 2/100 (7 x .10) + (2 x .01) Write this number in standard form 0.267 2 x (1/10) + 6 x (1/100) + 7 x (1/1000) Write two more equivalent forms for this number. 267/1000 2/10 + 6/100 + 7/1000 0.2 + 0.06 + 0.007 Wicomico County Board of Education 2014-2015 Grade 5 17 Unit 2 The table below shows the times each grade took to complete a Math Olympics Task. The 2nd grade completed their task in a time longer than the 4th grade but less than the 1st grade. Write a possible time in the table in which the second graders could have completed the Math Olympics Task. Grade Minutes 1 8.406 2 8.401,8.402, 8.403, 8.404, and 8.405 3 8.045 4 8.4 Use a number line model to show how you know you are correct. 1st Grade 8.406 8.4 8.405 8.410 4th Grade Acceptable answers Wicomico County Board of Education 2014-2015 Grade 5 18 Unit 2 The Wilson Family owns four dogs. These are the weights in pounds of the four dogs: 51.6 51.06 51.066 51.549 Write the decimals in order from least to greatest. 51.06 , 51.066, 51.549, 51.6 Use what you know about decimals to explain how you ordered the decimal numbers. Answers may vary. Students may include a number line or a representation of the numbers using base ten blocks, or a place value table to prove their answer. Wicomico County Board of Education 2014-2015 Grade 5 19 Unit 2 Bob is making a snack tray for a party. He bought two packages of cheese, ½ pound of Swiss and 3/5 of a pound of Cheddar. Bob also bought 0.8 pound of ham, 0.75 pound of turkey, and 0.375 pound of salami. Write the foods in order from least to greatest weight. Students may convert all of the weights to equivalent fractions and or decimals in order to compare the foods. Food Fraction Swiss ½ Equivalent Fraction 500/1000 Cheddar 3/5 600/1000 .600 Ham 8/10 800/1000 .800 Turkey 75/100 750/1000 .750 Salami 375/1000 375/1000 .375 Decimal .500 Use this number line to show how you would round 14.375 to the nearest tenth. 14.375 14.3 14.350 14.370 14.4 14.375 is between 14.3 and 14. Since 14.375 is closer to 14.4than 14.3, it would round to 14.4. Wicomico County Board of Education 2014-2015 Grade 5 20 Units 2 & 3 A race is limited to 1,000 cyclists divided into 8 equal groups. Each group will start the race at a different time. The first group starts at 8:00 AM, the second group starts at 8:15 AM, the third group starts at 8:30 AM, and so on. Write and model a decimal number for the fraction of the 1,000 cyclists that is represented by each group. What time will the last group start the race? 1000 ÷ 8 = 125. Each group consists of 125 cyclists. This can be represented as a fraction and decimal; 125/1,000 and 0.125. The last group of cyclists will begin the race at 9:45. Wicomico County Board of Education 2014-2015 Grade 5 21 Unit 3 Carolina’s Banana Pudding Recipe Ingredients 2 cups sour cream 5 cups whipped cream 3 ¾ cups vanilla pudding mix 4 cups milk 8 bananas Carolina is making her special banana pudding recipe. She is looking for her measuring cup, but can only find the "1/4 cup container." Step A: How many times must she fill the "1/4 cup container" to put in the correct amount of sour cream? Draw a picture to illustrate your solution, and write an equation that represents the situation. Step B: Carolina does not remember in what order she added the ingredients but the last ingredient added required 16 quarter cups. What was the last ingredient Carolina added to the pudding? Draw a picture to illustrate your solution, and write an equation that represents the situation. The purpose of this task is to provide students with a concrete situation they can model by dividing a whole number by a unit fraction. For students who are just beginning to think about the meaning of division by a unit fraction (or students who have never cooked), the teacher can bring in a 1/4 cup measuring cup so that students can act it out. Students may need a great deal of practice seeing the connection between the visual representation and the more abstract equations. This task provides an excellent opportunity for teachers to emphasize the relationship between multiplication and division, and if students do not automatically see the connection, the teacher should draw their attention to it. The approaches described in the solution can be used to make the connection between dividing by a whole number and multiplying by its reciprocal. If students are just beginning to understand the meaning of dividing by a unit fraction, such a conversation should be postponed. However, if they feel comfortable solving these kinds of problems with pictures, this task provides a perfect opportunity to see that dividing a whole number by a unit fraction is the same as multiplying by the reciprocal of the unit fraction. This, in turn, prepares them for the more general result that dividing by any fraction is the same as multiplying by its reciprocal, which students will see in 6th grade. Wicomico County Board of Education 2014-2015 Grade 5 22 1. Carolina would need to fill the "1/4 cup container" with sour cream 8 times because (as we can see in the picture below), there are 4 "1/4 cups" in 1 cup, and so it takes 2×4=8 "1/4 cups" to make 2 cups: This is a "how many groups?" division problem because it asks "How many '1/4 cups' are in 2 cups?" There are two correct equations: 2÷1/4= ? or equivalently: ?×1/4=2 We can verify that 8 is the correct solution by noting that 8×1/4 equals 2. 2. We can think of this problem several ways. First, we can ask, "How many cups did I start with if I ended up with 16 '1/4 cups'?" We could write an equation for this: ? ÷14=16 We could also say, "I have 16 '1/4 cups', and I want to know how many cups this is, so I can multiply 16 and 1/4 to find the number of cups I started with." This can be represented by the following equation: 16×1/4= ? Notice that these two equations are equivalent and can both be interpreted in terms of the following picture: Here is yet another approach: If we note that there are 4 "1/4 cups" in 1 cup, we can also think of this as a "how many groups?" division problem. We know that there are a total of 16 "1/4 cups," and that there are 4 "1/4 cups" in a cup (a group), and we want to know how many cups (or how many groups) this makes. Here the equation is: 16÷4=? Since 16÷4=4, she must have milk as the last ingredient. Wicomico County Board of Education 2014-2015 Grade 5 23 Unit 3 Draw a visual model to solve this problem. Darrien took a Science test on Friday. Three-eighths of the questions were multiple choice and one-fourth of the questions were true-false. What fractional part of the total number of questions were either multiple choice or true-false questions? Four Possible Models that show 3/8 + ¼ = 5/8: Set Model Two Hexagons make the whole An Area Model Wicomico County Board of Education Cuisenaire Rods 2014-2015 Grade 5 24 Unit 3 Emilio rides 7/8 mile from his house to his friend Jake’s house. Together they ride 1/4 mile to school. How far does Emilio ride to school that day? Use a visual model to prove your answer is correct. 7/8 + 1/4 = 7/8 + 2/8 = 9/8 miles or 1 1/8 miles (Although students may write their answer as a mixed number, it is not expected or required.) Four Possible Models that show 7/8 + 1/4 = 9/8: Set Model Two Hexagons make the whole 7/8 ¼ = 2/8 An Area Model Wicomico County Board of Education Cuisenaire Rods 2014-2015 Grade 5 25 Unit 3 The difference between two mixed numbers with unlike denominators is 3 5/8 . What might the two mixed numbers be? Show as many different solutions as you can. Explain your strategy for finding solutions. Answers may vary. One possible solution is 5 3/4 - 2 1/8 = 3 5/8. Students should use manipulatives such as pattern blocks, fraction circles or squares, or Cuisenaire rods to model this problem. Wicomico County Board of Education 2014-2015 Grade 5 26 Unit 3 3 A cornbread recipe calls for cup of milk. Rachel uses the 4 5 last cup of milk in one carton. She opens another carton and 8 pours the remaining amount needed. How much milk does Rachel use from the newly opened carton? Four Possible Models that show 3/4 – 5/8 = 1/8: Set Model Two Hexagons make the whole 3/4 3/4 = 6/8 take away 5/8 and 1/8 is left Begin with 3/4 then turn it into an equivalent fraction of 6/8 then take away 5/8. An Area Model Cuisenaire Rods The white rods represent eighths. The red rods represent fourths The brown rod represents the whole. Wicomico County Board of Education 2014-2015 Grade 5 27 Unit 3 Mom bakes a chocolate flavored cake, a vanilla flavored cake, and a strawberry flavored cake. Each cake is the same size. Angela eats four-eights of the chocolate cake, two-eighths of the vanilla cake and two-fourths of the strawberry cake. David eats one-fourth of the chocolate cake, three-eighths of the vanilla cake, and one-half of the strawberry cake. Who eats the most cake? How much of each cake is left? Show all of your mathematical thinking. A A A A A A D D D D Chocolate D Vanilla A A A A D D D D Strawberry Angela ate 10/8 and David ate 9/8. Angela ate more cake than David. The chocolate cake has 2/8 left and the vanilla cake has 3/8 left. There is no strawberry cake left. Wicomico County Board of Education 2014-2015 Grade 5 28 Unit 3 If the whole bar is 3 units long, what is the length of the shaded part of the bar? Write a multiplication equation for the diagram, and then solve. 0 Circle the expression(s) that are equal to 3 5 × 6. Explain why the others are not equal using words, pictures, or numbers. a. 3 × (6 ÷5) b. 3 ÷ (5 × 6) = 3 ÷ 30 = 0.1 c. (3 × 6) ÷5 d. 3 × 6 5 Wicomico County Board of Education 2014-2015 Grade 5 29 Unit 3 Jackson claims that multiplication always makes a number bigger. He gave the following examples: If I take 6, and I multiply it by 4, I get 24, which is bigger than 6. 1 2 1 If I take , and I multiply it by 2 (whole number), I get , or which 4 4 1 2 is bigger than . 4 Jackson’s reasoning is incorrect. Give an example that proves he is wrong, and explain his mistake using pictures, words, or numbers. Draw a visual model to solve this problem. Helen gave her son Matt two hot dogs for dinner. She cuts each hot dog into sixths. Matt eats all but half of the last piece. How much of his dinner is left? Each hot dog is cut into sixths, however both of the hot dogs make the whole dinner. Therefore the pieces of hot dog represent twelfths. If Matt eats all but ½ of a twelfth, then he left 1/24 of his dinner. Use two pattern blocks to represent the hot dogs. Each pattern block can be divided into sixths with the green triangle. The whole becomes twelfths. Matt eats all of the pieces except half of the last twelfth. Half of the last twelfth would be represented by the purple triangle. Since it takes 24 purple triangles to make the whole, Matt left 1/24 of his dinner. Half of the last piece would be a purple triangle. The purple triangle represents 1/24 of the whole which is two hexagons. Wicomico County Board of Education 2014-2015 Grade 5 30 Unit 3 Draw a visual model to solve and represent this problem. Sophie’s gave Mike 1/2 of a candy bar. Mike ate 1/3 of it. How much did he eat? 1/6 of the whole candy bar Draw a visual model to solve and represent this problem. 3 The Smith’s garden covers of an acre. One third of the garden is 4 vegetables, and the rest is flowers. What part of the acre is planted in flowers? 6/12 of the acre is planted in flowers 1/3 vegetables Wicomico County Board of Education 2014-2015 Grade 5 31 Unit 3 Draw a visual model to solve and represent this problem. Kim is at the movies with her friend. The movie lasts 2 hours long. 3 Kim’s friend decided into the movie that she wanted some popcorn. 4 How long did they watch the movie, before getting popcorn? _______ Each hexagon represents an hour of the movie. Since the movie lasts 2 hours, the whole is represented by both hexagons. A red trapezoid represents a fourth of the whole. Three trapezoids represent 3/4. This 3/4 would be an hour and a half into the movie. Another possible model using Cuisenaire rods: 3/4 of the whole 1 hour 1 hour whole Wicomico County Board of Education 2014-2015 Grade 5 32 Unit 3 Draw a visual model to solve and represent this problem. 4 4 5 5 At lunch Gloria ate of a bag of potato chips, Suzie ate of a bag 1 of potato chips, and John ate of what Suzie ate. How many bags 2 of potato chips did they eat in all? _________ The first step would be to calculate the amount of chips John ate. John ate1/2 of 4/5: 1/2 x 4/5 = 4/10 Then add the amount of potato chips eaten by Gloria, Suzie, and John. 4/5 + 4/5 + 4/10 8/10 + 8/10 + 4/10= 20/10 Two whole bags of potato chips were eaten. Wicomico County Board of Education 2014-2015 Grade 5 33 Unit 3 Draw a visual model to solve this problem. 3 Megan has yard of green felt to use on two bulletin boards. 4 She wants to use the same amount of felt on each board. How much felt will she use on each bulletin board? 1 yard of green felt This task focuses on dividing a fraction by a whole number ¾ ÷ 2 or the inverse which would be multiplying a fraction by a fraction ½ of ¾. Students may begin by using manipulatives such as paper or pattern blocks to model the problem. Students should then transfer their model to a representation. Each bulletin board will be covered with 3/8 yard of felt. Wicomico County Board of Education 2014-2015 Grade 5 34 Unit 3 Kulani is painting his room. He needs 1/3 of a gallon to paint the whole room. What fraction of a gallon will he need for each of his 4 walls if he uses the same amount of paint on each? Explain your work and draw a picture to support your reasoning. In order to find out what fraction of a gallon of paint Kulani will use on each wall, we need to divide the amount of paint that he has, 1/3 of a gallon, by 4. We know that the fraction 1/3 represents 1 piece where 3 equal pieces make a whole gallon. We can draw a rectangle that represents a whole gallon and shade 1/3 of it to represent the amount of paint he has. If we divide each of the 3 equal pieces in the picture into 4 smaller, equal-sized pieces, then the whole gallon is now divided into 4×3=12 equal pieces. This means that one of these new, smaller equal pieces represents the fraction 1/12: Note that by dividing every third into 4 equal pieces, we divided the 1/3 that represents Kulani's paint into 4 equal pieces, and in particular each of these pieces is 1/12 of the whole gallon. This means that 1/3÷4=1/12. Based on our understanding of the relationship between multiplication and division, we can also see that 4× 1/12= 1/3. So Kulani will need to use 1/12 of a gallon of paint on each wall. Wicomico County Board of Education 2014-2015 Grade 5 35 Unit 3 Salad Dressing Recipe 1/3 cup olive oil 1/6 cup balsamic vinegar a pinch of herbs a pinch of salt Makes 6 servings 1. How much salad dressing will this recipe make? Write an equation to represent your thinking. Assume that the herbs and salt do not change the amount of dressing. 2. If this recipe makes 6 servings, how much dressing would there be in one serving? Write a number sentence to represent your thinking. The purpose of this task is to have students add fractions with unlike denominators and divide a unit fraction by a whole number. This accessible real-life context provides students with an opportunity to apply their understanding of addition as joining two separate quantities. Additionally, the context presents a "how many groups" division problem where a unit fraction should be divided into 6 equal groups. 1. The total amount of dressing can be found by adding the oil and vinegar (since the other two ingredients won't change the amount). Here is a picture that represents the amount of oil: and here is a picture that represents the amount of vinegar: We can show the sum like this: Wicomico County Board of Education 2014-2015 Grade 5 36 Unit 3 After a class potluck, Emily has three equally sized apple pies left and she wants to divide them into eight equal portions to give to eight students who want to take some pie home. Draw a picture showing how Emily might divide the pies into eight equal portions. Explain how your picture shows eight equal portions. What fraction of a pie will each of the eight students get? Explain how the answer to (b) is related the division problem 3÷8. The purpose of this task is to help students see the connection between a÷b and ab in a particular concrete example. The relationship between the division problem 3÷8 and the fraction 3/8 is actually very subtle. 3÷8 is the number you multiply 8 by to get 3. 3/8 is the number you get by taking 3 copies of the unit fraction 1/8. So 3÷8 is defined in terms of multiplication, and 3/8 is defined in terms of unit fractions. It is not obvious that these two numbers are the same, so students need opportunities to see that they will necessarily always be the same. Note that if b people share a pies equally, then each person will get a/b of a pie by the same kind of reasoning shown in the solution below. Below is a picture of how Emily might divide the three apple pies into eight equal portions. Here each color (yellow, orange, red, green, blue, dark purple, light purple, and light blue) represents one portion. So each portion consists of three pieces of pie and each piece of pie represents 18 of a full pie: Because these pies are all the same size and they are all apple pies, Emily does not need to give each student one piece of each of the three pies: two or three pieces of the same pie could go to one student. This picture, however, shows clearly that the pies have been divided into eight equal portions. If multiple pieces of a particular pie were to go to the same student, it would be necessary to analyze the picture more closely and count how many slices of pie each student received to check that it has been divided evenly. As the picture shows, each portion consists of three slices of apple pie. Since these slices represent 1/8 of a pie, this means that each student gets 3/8 of an apple pie. If 3 pies are divided into 8 equal portions, then 8 of these portions makes 3 pies, a fact that is clearly illustrated in part (a). We can write this in symbols if we use a question mark to represent the amount of pie in one portion: 8×?=3 When we know a factor and the product, we can find the other factor by dividing: 3÷8=? So one person's portion is whatever we get when we divide 3 by 8. In part (b), we saw that one portion is 3/8. So that means that 3÷8=3/8. Wicomico County Board of Education 2014-2015 Grade 5 37 Unit 4 The following equations involve different quantities and use different operations, yet produce the same result. Use a place value mat and words to explain why this is true. 4.13 x 103 = 4130 Wicomico County Board of Education 413,000 ÷ 102 = 4130 2014-2015 Grade 5 38 Unit 4 Joaquin hiked 0.56 mile in the morning and 1.45 miles in the afternoon. Joaquin wants to record in his journal how many miles he hiked altogether and how much farther he hiked in the afternoon. What distances should he put in his journal? Use base ten blocks to represent this addition and subtraction problem: + = Joaquin hiked 2.01 miles altogether. _ = Joaquin hiked 0.89 miles farther in the afternoon Wicomico County Board of Education 2014-2015 Grade 5 39 Unit 4 The cost of making money varies from coin to coin: Pennies 0.8 cents each Nickels 2.9 cents each Dimes 1.7 cents each Quarters 3.7 cents each Half dollars 7.8 cents each What is the cost of making $5.00 worth of each coin? It may be helpful to suggest students make a table to organize their information. Students need to determine how many of each coin it takes to equal $5.00. Then they multiply that number by the cost. Coin Penny Nickel Dime Quarter Half-dollar Number of Coins Needed to Make $5.00 500 100 50 20 10 Wicomico County Board of Education Cost to Make One Total Cost 0.8 2.9 1.7 3.7 7.8 $4.00 $2.90 $0.85 $0.74 $0.78 2014-2015 Grade 5 40 Unit 4 The table shows four people who earn the typical amount for their education level. Name Level of Education Weekly Income Miley Drop out High School Graduate 2-Year College Graduate 4-Year College Graduate $440.50 Niko Taylor Pinky $650.35 $771.25 $1,099.20 How much money will Pinky earn in a month? About how long will Miley have to work to earn the same amount? There are four weeks in a month. Pinky makes $1099.20 in a week so she will make 4×1099.20=4×1100−4×0.80=4400−3.20=4396.80 Pinky will make $4396.80 in a month. We can divide this by how much Miley makes in one week to find out how many weeks she will have to work. 4396.8÷440.5≈4400÷440=10 Miley will have to work about 10 weeks, or two and a half months, to earn the same amount that Pinky will make in one month. Wicomico County Board of Education 2014-2015 Grade 5 41 Unit 4 Kevin works in a factory. He has to make 3.2 car parts in an hour to make the number of parts needed in a 6.5 hour workday. Use an area model to show how many parts Kevin should make in one day. 6 x 3 = 18 15 x .10 = 1.5 10 x .01 = .10 12 x .10 = 1.2 18.00 1.20 1.50 0.10 Partial Products 20.80 Students will use mathematical tools and model with mathematics as they use base ten blocks to make the area model for 3.2 x 6.5. They attend to precision as they transfer their model to the representation and determine the total of the partial products shown in their models. Wicomico County Board of Education 2014-2015 Grade 5 42 Unit 4 Sarah says that 26 ÷ 8 equals 14 ÷ 4 because both are “3 R2.” Explain her mistake using decimal division. Wicomico County Board of Education 2014-2015 Grade 5 43 Unit 5 Mr. Schmidt used 10 buckets to collect rainfall in various locations on his property. The following line plot shows the amount of rain collected in each bucket in gallons. Write an expression that includes multiplication to show how to find the total amount of water collected in gallons. Then solve your expression. Rainfall Collected Gallons Wicomico County Board of Education 2014-2015 x = 1 bucket Grade 5 44 Unit 5 The students in Raul’s class were growing grass seedlings in different conditions for a science project. He noticed that Pablo’s seedlings were 11/2 times a tall as his own seedlings. He also saw that Celina’s seedlings were 3/4 as tall as his own. Which of the seedlings shown below must belong to which student? Explain your reasoning. Since Pablo’s seedlings are 11/2 times a tall as Raul’s, Pablo’s seedlings must be taller than Raul’s. Pablo’s seedlings looks like Raul’s seedlings scaled by a factor larger than 1. Since Celina’s seedlings are 3/4 as tall as Raul’s, Celina’s seedlings must be shorter than Raul’s. Celina’s seedlings looks like Raul’s seedlings scaled by a factor smaller than 1. Celina’s seedlings are shorter than Raul’s and Pablo’s are taller than Raul’s. Thus, the seedlings in pot A belong to Celina, the seedlings in pot B to Raul, and the seedlings in pot C belong to Pablo. Wicomico County Board of Education 2014-2015 Grade 5 45 Unit 5 Mrs. Williams uses the following recipe for crispy rice treats. She 2 decides to make of the recipe. 3 2 cups melted butter 24 oz marshmallows 13 cups rice crispy cereal Step A: How much of each ingredient will she need? Write an expression which includes multiplication. Solve by multiplying. Step B; How many fluid ounces of butter will she use? Wicomico County Board of Education 2014-2015 Grade 5 46 Unit 5 Step C: When the crispy rice treats have cooled, Mrs. Williams cuts them into 30 equal pieces. She gives two-fifths of the treats to her son and takes the rest to school. How many treats will Mrs. Williams take to school? Use any method to solve. Luke had a calculator that will only display numbers less than or equal to 999,999,999. Without solving these problems, which of the following products will his calculator display? Explain. 1. 2. 3. 4. 792 × 999,999,999 ½ × 999,999,999 15/4 × 999,999,999 0.67 × 999,999,999 It is much easier to answer the question if you can think of multiplying a number by a factor as scaling the number. Since multiplying a positive number by a factor greater than 1 always results in a larger number, the first and third products will be too large to display. Since multiplying a positive number by a factor less than 1 (but greater than zero) always results in a smaller number, the second and fourth products will be displayed on his calculator. Wicomico County Board of Education 2014-2015 Grade 5 47 Unit 5 Draw a visual model to solve this problem. A parking space for a school bus measures 15 3/4 yards long and 4 1/2 yards wide. What is the area of the parking space? 4 ½ yards To find the area of the parking space add the partial products: 15 ¾ yards 60+ 7 ½ + 3 + 3/8 = 70 7/8 sq yards 15 x 4= 60 sq yards 15 x ½ = 7 ½ sq yards ½ x ¾ = 3/8 sq yards yards ¾ x 4 = 3 sq yards Wicomico County Board of Education 2014-2015 Grade 5 48 Unit 6 Read the statements. Circle “True” or “False.” Explain your choice for each using words and/or pictures. a. All parallelograms are quadrilaterals. True False True False A parallelogram is a kind of quadrilateral with 2 sets of parallel sides. b. All squares are rhombuses. A rhombus has 4 equal sides, and so does a square. But not all rhombuses are squares. c. Squares are rhombuses, but not rectangles. True False Squares are both because they also have 4 right angles. d. The opposite angles in a parallelogram have the same measure. True False It’s because the sides are parallel to each other and they have to add to 360, so both pairs have to be the same. e. Because the angles in a rectangle are 90, it is not a parallelogram. The sides are still parallel pairs, so it’s a parallelogram. True False f. The sum of the angle measures of any trapezoid is greater than the sum of the angle measures of any parallelogram. The angle measures of any quadrilateral, including trapezoids and parallelograms is always 360. True False g. The following figure is a parallelogram. True False 115 60 The angles would have to add up to 180, but they only make 175. This would mean all the angles together would make 350 degrees, which is impossible. They must total 360 degrees. Wicomico County Board of Education 2014-2015 Grade 5 49 Unit 6 How many DIFFERENT quadrilaterals can be made by joining the dots on these circles? Classify these quadrilaterals. Students should have an opportunity to make quadrilaterals and other shapes with toothpicks or geoboards prior to completing this activity. Clarify that drawing a congruent shape but using different dots does not count as a different shape. Students may look for and make use of structure by beginning with the same dot and joining different dots to make new quadrilaterals. Wicomico County Board of Education 2014-2015 Grade 5 50 Unit 7 Using the order of operations and parentheses, write at least three expressions which equal 27. Possible solutions: (2 + 7) x 3 = 27 (2 x 10) + ( 3 + 4) = 27 (5 x 3) + (4 x 3) = 27 Evaluate this equation. Is it correct or incorrect? How do you know? 3 x (18 – 3) + (6 + 4) ÷ 2 = 50 3 x (15) + (10) ÷ 2 45 + 5 = 50 Wicomico County Board of Education 2014-2015 Grade 5 51 Unit 7 Write an expression using grouping symbols to find how many sides 6 triangles, 4 hexagons, and 5 quadrilaterals have altogether. (6 x 3) + ( 4 x 6) + ( 5 x 4) = X 18 + 24 + 20 = 62 sides What is the value of the x? 3 x (8 + 1) - 12 ÷ 3 = x x = 23 If the parentheses in the expression above were removed, explain how the value of the expression would change. Use words, numbers, and/or symbols in your explanation. If the parentheses are removed, the value of the expression changes to 21 Write an expression which equals 50. You must use all four operations at least once and at least one set of parentheses in your expression. Possible answer: (5 x 10) + (20 ÷ 4) – 5 = 50 Wicomico County Board of Education 2014-2015 Grade 5 52 Unit 8 Complete the table for the rule multiply by 2 then add 2 for the values of 𝑥 from 0 to 4. Then use the coordinate plane to answer the questions. 𝒙 𝒚 (𝒙, 𝒚) 0 2 (0,2) 1 4 (1,4) 2 6 (2,6) 3 8 (3,8) 4 10 (4,10) e a. Which line shows the rule in the table? Line a b. Give the coordinates for the intersection of lines 𝓫 and 𝓬. (2,6) c. Draw a line on the graph such that any point on the line has a 𝑦-coordinate of 2. Label your line as 𝒆. d. Which coordinate is 2 for any point on line 𝓬? The x-coordinate e. Kim and Lacy want to draw a line on the coordinate plane that is parallel to line 𝓪. Kim uses the rule, multiply by 4 and add 2 to generate her 𝑦-coordinates. Lacy uses the rule multiply by 2 and add 4 to generate her y-coordinates. Which girl’s line will be parallel to line 𝓪? Without graphing the lines, explain how you know. Lacy’s rule will make a line parallel to line a. The rule for a is multiply x by 2, add 2. The rule for Lacy’s line is multiply x-coordinate by 2 and add 4. Lacy’s line is parallel because the steepness of the line is the same. The multiplication part of the rule is the same. The adding part of the rule will make the y-coordinates two more than those in line a. Wicomico County Board of Education 2014-2015 Grade 5 53 Unit 8 An airplane is descending into an airport. When its altitude is 5 miles, it is 275 miles from the airport. When its altitude is 4 miles, it is 200 miles from the airport. At 3 miles, it is 125 miles from the airport. 5 mi The plane’s altitude will be 2 miles 4 mi Step B: For the plane to land at the airport, the altitude will need to be 0 and the distance from the airport will need to be 0. Should the pilot continue this pattern? Why or why not? Altitude Step A: If the pilot follows the same pattern, what will the plane’s altitude be at 50 miles from the airport? 3 mi 2 mi 1 mi 50 The pilot should not continue this pattern. If the pilot continues this course the plane will be past the airport when it reaches 0 altitude. Wicomico County Board of Education 2014-2015 100 150 200 Miles from Airport Grade 5 54 250 Unit 9 2 In the diagram, the length of S is the length of T. If S has an area of 3 368 cm2, find the perimeter of the figure. S Wicomico County Board of Education 16 cm T 2014-2015 Grade 5 55 Unit 10 Mrs. Hinoj had 75 feet of ribbon. If each of the 18 students in her class gets an equal length of ribbon, how long will each piece be? Write your answer. Using only feet, Using a whole number of feet and a whole number of inches, and Using only inches. Each student will get a piece of ribbon that is 4 1/6 feet long, which is also 4 feet 2 inches or 50 inches. In this problem the whole set consists of the ribbon and the number of subsets is 18, namely the number of students in the class. The student must know that there are 12 inches in one foot to complete the problem. Wicomico County Board of Education 2014-2015 Grade 5 56 Unit 10 James M. Bennett is replacing the existing grass soccer field with a new type of grass. They are looking for the best buy for their money. Below are price quotes from various local nurseries: 6’ x 2’ roll $1.50 6’ x 4’ roll $3.50 6’ x 5’ roll $4.00 8’ x 2’ roll $2.00 The field dimensions are 120ft x 160 ft How many rolls of sod will be needed for each size? What will be the total cost of the sod for each size? Which is the best buy? If the truck which delivers the sod holds a maximum of 1500 rolls, and charges $100 for each trip, which is the best buy? (Optional) Make a scale diagram of how the sod will be laid down on the field. Roll Size 6’ x 2’ 6’ x 4’ 6’ x 5’ 8’ x 2’ Number of Rolls Needed 1600 800 640 1200 Cost Per Roll Total Cost $1.50 $3.50 $4.00 $2.00 $2400.00 $2800.00 $2560.00 $2400.00 The 6’ x 2 and 8’ x 2’ sizes will be the best buy, however once the delivery charge is added the 8’ x 2’ size would cost the least because it would take two deliveries for the 6’ x 2’ size which would add an additional $200 to the cost. The 8’ x2’ size would require only one delivery which would be an additional $100 in cost. Wicomico County Board of Education 2014-2015 Grade 5 57 Unit 10 Five fifth grade classes are planning n end-of-the-year celebration. There are a total of 120 students invited to the celebration. The teachers have decided to rent tables and chairs from the local Rent-ACenter. They charge $15 per square table and $8 per chair. The square tables can seat 2 people on each side. Write an expression for all the ways you could arrange the tables to seat 120 people. Use pictures and charts for your solution. Find the largest number of tables as well as the smallest number of tables that could be used to seat 120 people.Calculate the cost of the different seating arrangements. 15 of these 6 of these 10 of these Number Cost Number Cost of of of of Tables Tables Chairs Chairs Total Cost 15 $225 120 $960 $1185 20 $300 120 $960 $1260 24 $360 120 $960 $1320 15 x 8 = 120 10 x 12 = 120 6 x 20 = 120 Wicomico County Board of Education 2014-2015 Grade 5 58 Unit 10 Miguel and Jacqui built towers out of craft sticks. Miguel’s tower had a 4-inch square base. Jacqui’s tower had a 6-inch square base. If Miguel’s tower had a volume of 128 cubic inches, and Jacqui’s had a volume of 288 cubic inches, whose tower was taller? Explain your reasoning. Wicomico County Board of Education 2014-2015 Grade 5 59 Unit 10 Jeanne makes hair bows to sell at the craft fair. Each bow requires 1.5 yards of ribbon. Step A: At the fabric store, ribbon is sold by the foot. If Jeanne wants to make 84 bows, how many feet of ribbon must she buy? Show all your work. Step B: If the ribbon costs 10¢ per foot, what is the total cost of the ribbon in dollars? Explain your reasoning, including how you decided where to place the decimal. Step C: A manufacturer is making 1,000 times as many bows as Jeanne to sell in stores nationwide. Write an expression using exponents to show how many yards of ribbon the manufacturer will need. Do not calculate the total. Wicomico County Board of Education 2014-2015 Grade 5 60