EDUC 271 Final, Fall 2005

American University of Beirut Dr. Nehme Safa January 23, 2006 Final Examination EDU 271 I. Find the sum of 87762base 9 + 8base 9 II. Which is greater 390+390+390 or 3100 ? III. Identify and describe the error in each calculation. Demonstrate the use of base ten blocks to show each error. a. 167 b. 37 _ 29 + 75 148 1012 IV. Use pattern to show that (-1).(-1)=+1 V. Use the charged field model to show that (-4). (-2)=+8 VI. For each of the following, find t if possible. If not possible, tell why. a. t3base 6= 33base ten b. 5t2base 7=262base ten c. t2base 7= 2t base ten VII. Would the clustering strategy of estimation be a good one to use in each of the Following cases? Why or why not? a. 474 +1467 +31 +2445 b. 483 +475 +530+503+528 Estimate parts (a) and (b) using the following strategies i. Front-End ii. Grouping to nice numbers VIII) The following calculations are incorrect. Explain how estimation might help you discover the error in one case but not in the other. a) 74 b) 48 * 23 * 32 212 96 148 124 1692 220 Which type of estimation strategy did you use? IX) You are a math teacher and you would like to teach integer subtraction . Suggest a set of strategies you can use to explain the above concept. GOOD LUCK