Problem 2
- 1. Rob Schupbach Problem #2 CRIN E07: Elementary Math Curriculum and Instruction Dr. Margie Mason September 17, 2011 Topic: Computation and Estimation: Factors and Mutliples—Grade 4 (SOL 4.4) Expected Heuristics: Choose an operation; Make table; Guess & check Tea with Mr. Tumnus—The Lion, The Witch, and The Wardrobe by C.S. Lewis Mr. Tumnus told Lucy about a midnight party of fauns and Dryads in the forest of Narnia. 35 fauns came to the party. There were 3 times as many Dryads as fauns. How many creatures were at the party? If the whole group split equally into 5 large circles for dancing, how many were in each circle? Answer: 140 creatures at the party and there were 28 dancers in each circle. Complete Solutions: For students who are not used to bar diagrams, the natural tendency is to multiply 3 x 35 = 105 creatures at the party. A quickly sketched diagram will show their error: There are four units in all, and 4 x 35 = 140. So 140 creatures were at the party. The second part of the problem is straight-forward. A diagram may not be needed, but here it is anyway: 140 ÷ 5 = 28. There were 28 dancers in each circle. Let’s Play Math. (2011). Retrieved September 17, 2011, from http://letsplaymath.net/ 1