NEW YORK TORONTO LONDON AUCKLAND SYDNEY MEXICO CITY NEW DELHI HONG KONG BUENOS AIRES

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1 Grade 6 NEW YORK TORONTO LONDON AUCKLAND SYDNEY MEXICO CITY NEW DELHI HONG KONG BUENOS AIRES

2 Scholastic Inc. grants teachers permission to photocopy the activity sheets from this book for classroom use. No other part of this publication may be reproduced in whole or in part, or stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without written permission of the publisher. For information regarding permission, write to Scholastic Inc., 557 Broadway, New York, NY Editor: Mela Ottaiano Cover design by Jason Robinson Interior design by Melinda Belter Illustrations by Teresa Anderko ISBN-13: ISBN-10: Copyright 2008 by Carole Greenes, Carol Findell, and Mary Cavanagh All rights reserved. Printed in China

3 Table of Contents ALGEBRA READINESS 6 INTRODUCTION PROBLEM SETS Inventions Perplexing Patterns Ticket Please Blocky Balance In Good Shape Numbaglyphics PROBLEM-SOLVING TRANSPARENCY MASTER SOLVE IT TRANSPARENCY MASTERS ANSWER KEY COLOR TRANSPRENCIES

4 Inventions Overview Students use clues and reason logically to figure out the value of the unknown represented by a letter. The value of the letter is used to complete the year of an invention. ALGEBRA READINESS 6 Algebra Solve for values of unknowns Replace letters with their values Problem-Solving Strategies Make a list of possible solutions Test possible solutions with clues Use logical reasoning Related Math Skills Compute with whole numbers Identify factors and multiples of numbers Identify odd and even numbers Math Language Digit Difference Factor Multiple Remainder Symbols: Less than <, Less than or equal to, Greater than >, Greater than or equal to, Not equal to Value Introducing the Problem Set Make photocopies of Solve the Problem: Inventions (page 11) and distribute to students. Have students work in pairs, encouraging them to discuss strategies they might use to solve the problem. You may want to walk around and listen in on some of their discussions. After a few minutes, display the problem on the board (or on the overhead if you made a transparency) and use the following questions to guide a whole-class discussion on how to solve the problem: 9

5 ALGEBRA READINESS 6 Name Date SOLVE PROBLEM Complete the year of the invention. Look at Clue 1. What does the symbol mean? (A is greater than or equal to 2 x 15, or 30.) Why did Ima use Clues 1 and 3 to make her list of possible values for A? (Clue 1 gives the least number possible, which is 30. Clue 3 gives the greatest number possible, which is 49; , or 98, is less than 100.) What are the numbers on Ima s list? (30, 31, 32,..., and 49) Which numbers on Ima s list match Clue 4? (31, 37, 41, 43, and 47) What are the factors of these numbers? (These numbers have only 1 and themselves as factors.) The Slinky was invented in the United States by Richard and Betty James in 19. The letter A stands for a 2-digit number. Use the clues to figure out the value of A. 1) A 2 x 15 2) The product of its digits is an even number. 3) A + A < 100 4) A has exactly two different factors. 5) The difference between the two digits of A is less than 3. I ll start with Clues 1 and 3, and make a list of values for A. The first three numbers are 30, 31, and What are all of the numbers on Ima s list? 2. What is A? Ima Thinker 3. How did you figure out the value of A? 4. Check your number with the clues. Show your work here. 5. Record A on the line below to complete the year of the invention. The Slinky was invented in the U. S. by Richard and Betty James in 19. Which of the numbers that have two factors match Clue 2? (41 because 4 x 1 = 4, 43 because 4 x 3 = 12, and 47 because 4 x 7 = 28.) Which of the numbers, 41, 43, and 47 match Clue 5? (43 because 4 3 = 1 and 1 < 3.) How can you check your answer? (Replace each A in the clues with its value. Be sure that the statements are true.) Work together as a class to answer the questions in Solve the Problem: Inventions. 11 Math Chat With the Transparency Display the Make the Case: Inventions transparency on the overhead. Before students can decide which character s circuits are connected, they need to figure out the answer to the problem. Encourage students to work in pairs to solve the problem, then bring the class together for another whole-class discussion. Ask: Who has the right answer? (Mighty Mouth) In what year was the television invented? (1923) How did you figure out the value of B? (From Clues 2 and 3, B can be 9 through 30. Clue 4 eliminates all numbers that have more than two factors leaving numbers 11, 13, 17, 19, 23, and 29. Clue 1 eliminates 11, 13, 17, and 19, leaving 23 and 29. Clue 5 eliminates 29.) How do you think CeCe Circuits got 29? (She probably ignored Clue 5.) How do you think Boodles got 14? (Boodles probably ignored Clue 4.) Name Date 12 MAKE CASE I believe that B is 23. Mighty Mouth Complete the year of the invention. The television was invented in the United States by Vladimir Zworykin in 19. The letter B stands for a 2-digit number. Use the clues to figure out the value of B. 1) The sum of the digits of B is not divisible by 2. 2) B ) B ) B has no factors except for 1 and itself. 5) The product of the two digits of B is a single-digit number. Boodles Obviously B is 29. Whose circuits are connected? Of course, B is 14. CeCe Circuits 10

6 Name Date SOLVE PROBLEM Complete the year of the invention. The Slinky was invented in the United States by Richard and Betty James in 19. The letter A stands for a 2-digit number. Use the clues to figure out the value of A. 1) A 2 x 15 2) The product of its digits is an even number. 3) A + A < 100 4) A has exactly two different factors. 5) The difference between the two digits of A is less than 3. I ll start with Clues 1 and 3, and make a list of values for A. The first three numbers are 30, 31, and What are all of the numbers on Ima s list? 2. What is A? Ima Thinker 3. How did you figure out the value of A? 4. Check your number with the clues. Show your work here. 5. Record A on the line below to complete the year of the invention. The Slinky was invented in the U. S. by Richard and Betty James in

7 Name Date MAKE CASE Complete the year of the invention. The television was invented in the United States by Vladimir Zworykin in 19. The letter B stands for a 2-digit number. Use the clues to figure out the value of B. 1) The sum of the digits of B is not divisible by 2. 2) B ) B ) B has no factors except for 1 and itself. 5) The product of the two digits of B is a single-digit number. 12 I believe that B is 23. Mighty Mouth Boodles Obviously B is 29. Whose circuits are connected? Of course, B is 14. CeCe Circuits