01:640:107 Lecture Notes - Lecture 15: Rational Number
Document Summary
Now that we have all four operations motivated and defined for the rational numbers, we consider both student interpretations (and misinterpretations) and uses of the operations in solving problems. Example 1 you show the students the following example to explain why 21/5 = 11/5, but one of the students says that it shows 11/15, not 11/5. Why would that interpretation be given, and how do you explain what is going on: o o o o. Note that the issue is identification of the meaning of the whole in the picture. If the whole is the entire picture, then the shaded parts represent 11/15. But if the whole is one of the sets of five circles, then the picture represents two wholes and 1/5 of the whole, i. e. the 21/5 = Also note that if a single circle represents the whole, then the shaded part of the picture represents 11.