90 p


Step 1: Calculating with rational numbers in real-world contexts


In the first event, the eighth graders are running a baton relay race with three other classmates. The team’s top speed for each leg is 56.81 seconds, 59.22 seconds, 57.39 seconds, and 60.11 seconds. Use the information to predict the team’s best time for the race. (2 points)










If the team’s best time for the race is less than 4 minutes, then the eighth graders earn 40 points. If not, the seventh graders earn 40 points. Which grade should be awarded 40 points?




Each leg of the race from part a is the same distance. Calculate the team’s average time for each leg of the race. Show your work. (2 points)










If the team’s average time is less than one minute per leg, then the eighth graders earn 50 points. If not, the seventh graders earn 50 points. Which grade should be awarded 50 points?



Step 2: Using properties of operations to add and subtract with fractions


a) Jill jumped "6" "1" /"3" feet in the long-jump event. Jill’s best friend jumped "6" "5" /"7" feet. How much farther did Jill’s best friend jump? Describe in words the process you used to solve the problem. (2 points)












If Jill’s best friend jumped farther than 6.5 feet, then she beat the school record and the seventh graders earn 50 points. If not, the eighth graders earn 50 points. Which grade should be awarded 50 points?




b) Claire and her partner, Grace, are throwing for the javelin event as a team. Claire threw the javelin 42"5" /"8" feet and Grace threw it 39"3" /"5" feet. How far did the team throw the javelin? Show your work. (2 points)









If the total distance of Claire and Grace’s javelin throw is greater than 82.5 feet, then the seventh graders earns 50 points. If not, the eighth graders earn 50 points. Which grade should be awarded 50 points?


For the high jump, each competitor receives multiple opportunities to clear the bar at each height. On average, Shane completes 2 out of 3 jumps on the lowest bar, 4 out of 6 jumps on the middle bar, and 1 out of 4 jumps on the highest bar. Write an equation that you could use to find Shane’s overall average number of jumps completed. Calculate Shane’s average using the equation. (2 points)







If Shane’s average number of jumps completed is greater than one-half, then the eighth graders earn 50 points. If not, the seventh graders earn 50 points. Which grade should be awarded 50 points?



Step 3: Using properties of operations to solve real-world problems with rational numbers


a) The next event requires each runner to jump 8 hurdles that are spaced 12.3 meters apart. If there are 15 meters from the starting line to the first hurdle and 10.5 meters from the last hurdle to the finish line, how long is the race? Show your work. (2 points)


15 m 10.5 m

Start Finish






Myra won the hurdles event for the seventh graders. She completed the race in 22.8 seconds and knocked down 1 hurdle. Byron won the race for the eighth graders. He completed the race in 20.3 seconds and knocked down 3 hurdles. If 2 seconds are added to the finishing time for each hurdle that is knocked down, what is the final



[ls answer if u know it

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Answer:

                             

Step-by-step explanation:

Answer:

1 - The sum of best times for the legs is 56.81 +59.22 +57.39 +60.11 = 233.53 seconds (3.89 minutes). Without additional information about the effects of training or the normal variation in times, this is the best prediction we can make.

2 - Since the team’s best time for the race is less than 4 minutes, the eighth graders earn 40 points.

3- 58.3825 (About 58) Average is found by adding all the data up and dividing by the amount of info there is. In this Case: 233.53 divided by 4 = 58.3825 which is around 58.

4- The seventh graders because the eighth graders got 58 which is more than 50 so the 7th grader would get the points

5- Kate’s best friend jumped 8/21 feet more than Kate did. First to find the difference between two fractions they need a common denominator, 21 works for this. Then the actual fractions need to match the denominator. 7/21 and 15/21 are our new fractions. Then when subtraction you subtract the numerators, the answer to that is 8/21 after simplifying (in this case you cant) you subtract the whole numbers, 6 – 6 = 0 the add the whole and fraction together. Kate’s best friend jumped 8/21 more feet than Kate did.

6- The seventh graders.

7- 42 5/8 + 39 3/5 Find common denominator for the fractions and rewrite them using the common denominator: 5/8 = 25/40 3/5 = 24/40 25/40 + 24/40 = 49/40 = 1 9/40 1 9/40 + 42 + 39 = 82 9/40 feet.

8- 9/40 = 0.225, plus 82 feet = 82.225 feet,  this is less than 82.5, so the 8th graders earned the 50 points.

9- The equation would be the total of completed jumps divided by the total number of attempts: (2 +4 + 1) / (3 + 6 +4) = 7/13 = 0.538 average.

10- 0.538 is greater than 1/2 ( 0.50), so the 8th graders earned 50 points.

11- The race is 111.6 m long. 8 hurdles spaced 12.3 m apart means 7 spaces that are 12.3 m in length; 7*12.3 = 86.1

Step-by-step explanation:

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