Teacher s Edition February 2010 Vol. 28, No.5 ISSN 0732-7773 Math at the Olympics The Olympic Games always provide exciting opportunities to teach meaningful math. On pages 6 7, students will learn about bobsledding. The gold-medal winner in the sport is decided by fractions of a second. Our fun activity on 4 5 explores the metric units of length that are used in many countries participating in the Olympics. Finally, our reproducible on page T4 has readers add decimals to compare world-class figure skaters. Let the games begin! Matt Friedman, Editor Content and Skills Guide Difficulty Level: H = Easy HH = On-Level HHH = Challenging PAGE ARTICLE TITLE, DIFFICULTY LEVEL PRIMARY MATH SKILL SUPPLEMENTARY SKILLS/APPLICATIONS Scholastic DynaMath 557 Broadway, Room 4052 New York, NY 10012 (212) 343-6458 DynaMath@Scholastic.com SUBSCRIPTION/DELIVERY INQUIRIES: 1-800-SCHOLASTIC (1-800-724-6527) www.scholastic.com/custsupport Issue Dates: 9/09 10/09 11 12/09 1/10 2/10 3/10 4/10 5-6/10 Cover Logic at the Hippolympics! H Logic line Problem solving 6, 7, 8 NCTM STANDARDS (See below for details) 2 3 Numbers in the News HH Mixed skills Computation, 5, 1, 2, 4, 7, 8 4 5 Metric Olympics H Appropriate metric units Measurement terms 1, 4, 7, 8, 9 6 7 Sledding for Gold H Ordering decimals Decimal place value 1, 4, 5, 8, 9 8 9 All the Presidents Pets HH Logic boxes Reasoning 6, 7, 8 10 11 Dig These Coordinates HH Reading a coordinate grid Algebra 1, 2, 4, 8, 9, 10 12 13 Secret Fraction Heroes! HH Simplest form of fractions Greatest common factor 1, 8 14 15 Having a Ball! HH Issue skills review Test-taking practice 1, 2, 4, 6, 7, 10 16 Selena s Prime Time H Prime numbers Factors 1, 8 T4 Great Skates! HH Decimal + pp. 4 8 extension 1, 7, 8 T5 Coordinate Creature HH Plotting ordered pairs pp. 10 11 extension 1, 4, 7, 8 T6 Great Uncommon Heroes H Greatest common factor pp. 12 13 extension 1, 8 Need Funding for DynaMath? Go to www.scholastic.com/classmags and click on Looking for Funding to learn how DynaMath qualifies for funding such as NCLB grants. 1. Number and Operations 2. Algebra 3. Geometry 4. Measurement 5. Data Analysis & Probability NCTM Standards 6. Problem Solving 7. Reasoning and Proof 8. Communication 9. Connections 10. Representation Standards listed above in a bold box (such as 1) indicate that the article also connects with a new NCTM Curriculum Focal Point. This Month at www.scholastic.com/dynamath Free bonus reproducibles Web resources related to this issue Index of skills covered this year 2009 2010 editorial planning calendar Printable Teacher s Edition PDFs of Mini-Lessons from this issue for Smart Board use A Supplement to Dynamath February 2010 DynaMath T1
Lesson plans COVER: LOGIC AT THE... EXTENSION: BONUS QUESTION After the race, Brice shared 16 rivergrass treats with Alice, Felice, and Dyson. He gave half of the treats to Alice. He gave half of what was left to Felice. After that, he gave half of what was left to Dyson. Brice kept the rest. How many treats did each hippo have? (Answer: Brice, 2; Dyson, 2; Felice. 4; Alice, 8) 2 3: NUMBERS IN THE NEWS BACKGROUND: I... CAN FLY The Tuskegee Airmen were the United States first group of African-American airmen, and they served in World War II. The group had a great influence on Kimberly Anyadike s decision to attempt her cross-country flight. One of the original Tuskegee Airmen, Levi Thornhill, joined Kimberly as her safety pilot on the flight. Discover more about the Tuskegee Airmen at: www.tuskegeeairmen.org/ It is important to emphasize that during 15-year-old Kimberly s flight, a safety pilot was onboard at all times. In the U.S., a person must be at least 16 years of age to fly solo. WEB SITE: GOOD CENTS Help students visualize huge numbers. At this site, see what different numbers of pennies, including a million, look like: www.kokogiak.com/megapenny/ 4 5: METRIC OLYMPICS EXTENSION: IDENTIFY OBJECTS For each incorrect multiple-choice answer in each question, have students identify an object that would be reasonable for that length. 6 7: SLEDDING FOR GOLD STRATEGY: ORDER DECIMALS Use different colors of sticky notes to denote place values from the ones place to the hundredths place. For example, write the ones-place digit and decimal point on a pink note, the tenthsplace digit on a green note, and the hundredths-place digit on a yellow note. Then have students arrange the notes so the place-value columns of each number align. 12 13: SECRET FRACTION... STRATEGY: DRAW A CIRCLE Emphasize the value of expressing fractions in simplest form. Tell students to draw a circle. Then tell them to shade in 17 of the circle. Pause for a moment before telling them to shade in 1_ of the circle 3 instead. After students have shaded in 1_ of the circle, show them how 17 3 51 can be simplified using the greatest common factor of 17 and 51: 17. EXTENSION: SHORTCUTS If the numerator of a fraction is prime, and it is not a factor of the denominator, the fraction is 51 in simplest form (example: 3_ ). If 8 the denominator of a fraction is a prime (and it is not equal to the numerator), the fraction is in simplest form (example: 4_ 7 ). If the difference between the numerator and denominator is 1, the fraction is in simplest form (example: 9 ). Have students simplify these fractions using the shortcuts: 3_ 5, 4_, 7_ 8 9, 12, 8_ 15 9. 10 14 15: HAVING A BALL! STRATEGY: TIP THAT WORKS! Estimate the answer to each problem after you first read it. Then solve. Compare your estimate with your final answer. If your estimate is not close to your final answer, look at the problem again to determine why the estimate and answer don t come close to matching. 16: SELENA S PRIME TIME STRATEGY: PRIME, COMPOSITE By definition, only natural numbers (counting numbers) are considered to be prime or composite. Therefore, decimals are neither prime nor composite. EXTENSION: BOOKMARK As a reference, have students make a prime-number bookmark that lists the 25 prime numbers from 2 to 97. Dale Beltzner Mr. Beltzner is the Math Subject Area Leader for the Southern Lehigh School District in Bethlehem, Pennsylvania. T2 DynaMath February 2010
Name SKILLS PAGE Problem of the Day Try one of these quick exercises each day as a fast, fun way to start your math lesson! TEACHERS: Make one copy per student, or assign one problem each day to start your math lesson! DAY 5 + = and = + + How many equal one? DAY 2 Find the value of q. 8 5 q = 144 DAY 1 Fill in the missing words: 2 + 5 = 75 cents DAY 10 If 8 inches of snow are equal to 1 inch of rain, how many inches of snow are equal to 6 inches of rain? DAY 4 Ann bought a pair of shoes. She got $3.65 back in change. She paid with a $20 bill. How much did the shoes cost? DAY 9 Which expression has the same value as 3 5 3 + 2? (1 + 2) 5 3 2 5 5 1 2 5 2 5 3 1 DAY 3 Take any number. Multiply it by 2. Add 2. Divide by 2. How does the final answer compare with the original number? DAY 8 Fill in the missing numbers: 4 2 6 3 12 10 14 7 2 0 4 2 8 6 DAY 7 What s my number? All three of my digits are the same. the sum of my digits is 6. DAY 6 All kimlerz are zligs. Some zligs are zumblens. Must all zumblens be kimlerz? DAY 15 Use mental math to fill in the blank. 326 5 5 = 10 5 DAY 14 JJ s number is 2 times TJ s. TJ s number is 2 times EJ s. The sum of all three numbers is 21. What is each person s number? DAY 13 A bell rings every 30 minutes. How many times does it ring in 1 day? DAY 12 Write the product of twenty-four and sixty in standard form. Try to do the math in your head! DAY 11 The temp. dropped 1 on Mon., 2 more on Tues., and 4 more on Wed. It was 20 on Wed. What was the temp. the last Sunday? DAY 20 What is the missing letter? Z, T, T, T, F,, S, S, E, N DAY 19 Kym got 2 e-mails on each even-numbered day this February and 3 on each odd-numbered day. How many e-mails did she receive in all? Day 18 In basketball, what are all the possible combinations of 2-point and/or 3-point shots that have a total of exactly 21 points? DAY 17 A cat eats 1_ 4 ounce of treats each day. How many days will it take the cat to eat 1 pound of treats? (Hint: 1 pound = 16 ounces) DAY 16 The high temperatures for five days were 78, 78, 83, 82, and 84. What was the average high temperature over those days? Problem of the Day by Dale Beltzner. Scholastic Inc. grants teachers permission to reproduce this page. 2010 by Scholastic. All rights reserved. February 2010 DynaMath T3
extension activity Great Skates! Name Figure skating is one of the most popular sports at the Winter Olympics. Rachael Flatt, a 17-year-old skater from Colorado, hopes to win gold for the American team! To do so, she ll have to show the judges her best spins, twists, and turns. And the judges will have to use math to give her a score. Add decimals to see how Rachael and other skaters did at the 2009 World Figure Skating Championships! What to Do 4 Read Figure Skating Scores. 4 Add each competitor s scores to find her final score for the event. Figure Skating Scores 4 Each figure skater skates in two rounds: a short program, and a free skate. 4 For each round, judges award points for different skating skills, and take away points for mistakes. The judges scores are added up to give the skater a score for that round. 4 The scores for each round are added together. The skater with the highest total wins gold! 4 When adding decimals, remember to line up the decimal points of the numbers you re adding. Example: At the 2009 World Figure Skating Championships, Laura Lepisto of Finland had a short-program score of 59.66 and a free-skate score of 110.41. What was her total score? 59.66 +110.41 170.07 2009 World Figure Skating Championships Final Scores Skater Short Free Final (Country) Program Skate A Miki Ando 64.12 126.26 (Japan) B Mao Asada 66.06 122.03 (Japan) C Rachael Flatt 59.30 113.11 (U.S.) D Yu-Na Kim 76.12 131.59 (South Korea) E Joannie Rochette 67.90 123.39 (Canada) supermath The highest score wins! Who won the... a. gold medal? b. silver medal? c. bronze medal? Activity by Bill Wise and Carli Entin. Scholastic Inc. grants teachers permission to reproduce this page. 2010 by Scholastic Inc. All rights reserved T4 DynaMath February 2010
Extension Activity Name Coordinate Creature Dive into this puzzle! Use coordinates to make a picture magically appear. 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 y You will sea a creature appear before your eyes! 1 x 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 What to Do 4 Plot each coordinate pair to the right on the grid. 4 When you plot a new coordinate, draw a line from the last coordinate you plotted to the new coordinate. 4 When you are finished, you should be able to see a picture! Begin A (0, 0) B (0, 1) C (1, 3) D (2, 5) E (3, 7) F (6, 11) Coordinates G (5, 13) H (7, 13) I (9, 12) J (13, 12) K (17, 10) L (19, 9) M (19, 8) N (17, 8) O (12, 7) P (9, 5) Q (8, 5) R (9, 7) S (6, 6) T (3, 4) U (5, 3) V (3, 2) W (1, 0) X (0, 0) End Activity by Dale Beltzner. Scholastic Inc. grants teachers permission to reproduce this page. 2010 by Scholastic Inc. All rights reserved. February 2010 DynaMath T5
extension activity Name Great Uncommon Heroes You know that Spider-Man can spin a web and Superman is superstrong. But not every comic-book hero is famous enough to be featured in a movie. Learn about some great uncommon heroes by working with greatest common factor. Greatest common factor 4 The greatest common factor, or GCF, is the greatest number that s a factor of two or more numbers. 4 To find the GCF, list the factors of each number. Circle the greatest factor those numbers share. Example: What is the GCF of 8 and 12? 4 Factors of 8: 1, 2, 4, 8 Factors of 12: 1, 2, 3, 4, 6, 12 4 The GCF is 4. What to Do 4 In each problem, find the GCF of the numbers in the blank. 4 Fill in the circle next to the correct answer. 4 The phrase next to the GCF completes the sentence about that comic-book superhero. 1 Medusa has the ability to 6, 9 A 6 talk with snakes. B 3 grow superstrong hair she can use to trap her enemies. 2 One of Amazing Man s amazing skills is 16, 20 A 4 turning himself into any material he touches. B 8 being able to breathe underwater. 3 Zatanna is a witch who casts spells by 25, 50 A 5 saying words that rhyme. B 25 saying words backward. 4When Billy Batson says Shazam, a lightning bolt changes him into 21, 32 A 1 Captain Marvel. B 11 Cosmic Boy. 5Thor Girl has superstrength and can fly, thanks to 48, 64 A 16 a source of magic billions of years old. B 8 her magic hammer. 6 Stone Boy can 36, 54, 90 A 9 use a magic ruby to make wishes come true. B 18 become as hard as stone but then he can t move on his own! Activity by Dale Beltzner and Carli Entin. Scholastic Inc. grants teachers permission to reproduce this page. 2010 by Scholastic Inc. All rights reserved. T6 DynaMath February 2010