Add and Subtract Decimals Through Thousandths. How can you record addition and subtraction of decimals through thousandths?

Transcription

1 ? Name 1.7 dd and Subtract ecimals Through Thousandths Essential Question How can you record addition and subtraction of decimals through thousandths? Number and Operations 5.3.K lso 5.3. MTHEMTIL PROESSES 5.1., 5.1.E Unlock the Problem t the 2010 Winter Olympics, rmin Zoeggeler won the bronze medal in the men s luge event. In his fastest run, he completed the first interval in seconds. It took him another seconds to reach the finish line. What was Zoeggeler s finish time? Underline the sentence that tells you what you are trying to find. ircle the numbers you need to use. dd decimals through thousandths THINK REOR Line up the numbers in each place. First, add the thousandths. Then, add the hundredths, tenths, ones, and tens. Regroup as needed. Place the decimal point in the sum. Houghton Mifflin Harcourt Publishing ompany Image redits: (cr) hristian Forcher/EP/orbis So, Zoeggeler s finish time was seconds. Try This! Use subtraction to check your work. Subtract one of the addends from the sum. ddition and subtraction are opposite, or inverse operations. You can use subtraction to check your answer to an addition problem. The difference should equal the other addend. Math Talk Mathematical Processes Why would you use paper and pencil instead of mental math to solve this problem? Module 1 41

2 Example Zoeggeler finished the first half of the run in seconds. The second half took only seconds. How many seconds faster was the second half of the run? Estimate = _ STEP 1 Line up the place values. Subtract the thousandths STEP 2 Subtract the hundredths. Subtract the tenths. Regroup as needed STEP 3 Subtract the ones and tens. Place the decimal point in the difference So, Zoeggeler was seconds faster in the second half of the run. To check subtraction using the inverse operation, add the number you subtracted to the difference. The sum should equal the number you subtracted from. Math Talk Mathematical Processes Explain how you know without adding that the sum of and 6.43 will result in a 5 in the thousandths place. Try This! Subtract. Then check your work Share and Show Houghton Mifflin Harcourt Publishing ompany

3 Name Problem Solving Practice: opy and Solve lgebra Find the unknown numbers in the pattern. Then write a description for the pattern , 3.3, 4.5, 5.7, _, 8.1, _ escription: , 4.00, 3.95, _, 3.85, _ escription: Houghton Mifflin Harcourt Publishing ompany Image redits: (tr) Image lub Graphics/Getty Images Problem Solving Use the table to solve Evaluate polo Ohno won the men s 500-meter speed skating final at the 2006 Winter Olympics. His time for the race was seconds. Francois-Louis Tremblay came in second, finishing second behind Ohno. What was Tremblay s time? 16. pply Jon Eley came in fifth in the men s speed skating final. How many seconds after polo Ohno did Eley finish? 17. Multi-Step The sum of two numbers is One number has a 4 in the tenths place and a 3 in the thousandths place. The other number has a 1 in the ones place and an 8 in the hundredths place. What are the two numbers? Men s 500-Meter Speed Skating Final Skater Time (in seconds). Ohno F. Tremblay H. hn E. edard J. Eley Write Math Show Your Work Module 1 Lesson 7 43

4 aily ssessment Task Mathematical Processes Fill in the bubble completely to show your answer. 18. Multi-Step Team spent seconds and seconds running a relay race. Team spent seconds and seconds running the relay race. Which statement is true? Team won by 0.17 second. Team won by 1.17 seconds. Team won by 0.17 second. Team won by 1.17 seconds. 19. Manuel is walking from his home to his school. He has walked mile so far and has mile left to walk. How far is Manuel s home from school? mile 0.12 mile 0.23 mile miles 20. Multi-Step Music & Movie Mart is selling used s for $6.99 each and used Vs for $8.49 each. You have $30 to spend. Which of these combinations could you buy? Two s and two Vs Three s and one V Three s and three Vs One and three Vs TEXS Test Prep 21. Toni has a ribbon that is 2.75 meters long. She cuts off meter. How much of the ribbon does Toni have left? meters meters meters meters Houghton Mifflin Harcourt Publishing ompany

5 Homework and Practice Name Number and Operations 5.3.K lso, 5.3. MTHEMTIL PROESSES 5.1., 5.1.E 1.7 dd and Subtract ecimals Through Thousandths Find the unknown numbers in the pattern. Then write a description for the pattern , 2.1, 3.2, 4.3. _ 6.5, 7.6 escription: , 5.00, 4.97, 4.94 _ 4.88 escription: Houghton Mifflin Harcourt Publishing ompany Problem Solving 12. bby finished a biking race in minutes. Juanita took minutes to finish. How much longer did bby take to finish the race than Juanita? 13. The sum of two numbers is One number has a 4 in the tenths place and a 7 in the thousandths place. The other number has a 1 in the ones place and an 2 in the hundredths place. What are the two numbers? Module 1 Lesson 7 45

6 Lesson heck TEXS Test Prep Fill in the bubble completely to show your answer. 14. ara spends $13.02 on sandals, $9.85 on shorts, and $15.20 on a hat. How much change does she receive back from $50? $10.93 $11.93 $11.34 $ Ling s relay team ran the first part of the race in seconds, the second part in seconds, and the third part in seconds. y how much did the relay team beat the champions, who ran the race in seconds? seconds seconds seconds seconds 16. Juan has a batting average of Gary has a batting average of What is the difference between the batting averages of the two baseball players? 17. Jonas is jogging from the park to the school. He has jogged mile so far. He has mile left to jog. How far is the park located away from the school? mile mile miles 0.40 mile 18. Multi-Step Jimmie adds 3.24, 4.294, and How much more than 5.31 is the sum? Multi-Step gallon of milk costs $3.32 and a container of orange juice costs $2.95. Max buys two gallons of milk and two containers of orange juice. How much does Max spend? $ $6.64 $12.54 $6.27 Houghton Mifflin Harcourt Publishing ompany