MAT 123A

Hand-in Assignment #3: 50 points

Due Thursday, April 6^th at the beginning of class

(If you know you will miss class, it is your responsibility to get your assignment into my mailbox in SB 308 before then)

Please work independently on the following problems. “Independently” means you may not receive help from tutors, friends, classmates or any other source (except from the instructor). Write up your solutions neatly on separate paper, clearly labeling all answers. Justify all answers. For explanations, please use complete sentences and standard grammar. If you have multiple pages they must be stapled together (not paper clipped) to receive full credit!

*For 3 points extra credit, type up your solutions!*

1. Suppose you are teaching your 4^th grade class how to convert a mixed number to an improper fraction. You give them the following example, with the spoken instruction:

“You multiply the 8 by 5, then add the three. Put that answer over 8 and that’s the improper fraction.” Those who follow the directions find the correct result, .

A student raises her hand and asks, “Why do we use that rule? I don’t understand it.”

How would you explain to this student why the rule always works? Use this example and several others along with definitions of mixed numbers and fraction addition to show why this rule works.

Also

Problems from textbook:

p. 256 18, 20, 28

p. 257 (Problems for Writing and Discussion) 2: Please write a detailed answer, including several examples to

illustrate your point.

p. 273 20, 26 (hint: try drawing a diagram)

p. 274 (Problems for Writing and Discussion) 1, 2; also include a clear explanation of your drawing for these

two problems.