Learning Exercises for Section 7.1
Embedding calculations in contexts like story problems is often helpful in keeping track of the unit. Compare these two problems. How do you think the misunderstanding in part (a) arises? A student thinks that because of his drawing in a cake-eating contest, Ann ate 1/4 of a cake and Bea ate 1/3 of a cake. How much cake did they consume in all?
Using a rectangular region as the unit, illustrate each calculation:
3 + 3/5
Model each of the sums on a number line:
a. b. 14 -
In his will, Thomas gave 1/3 of his estate to his daughter Jenny, 1/4 of his estate to his son Will, 1/6 of his estate to his granddaughter Karen, and the remaining amount to the American Heart Association. What part of Thomas's estate did the American Heart Association receive?
A wealthy woman's will calls for 1/5 of her estate to go to her favorite. What fraction of her estate is left for other beneficiaries?
A youngster mows his neighbor's yards. His lawnmower tank holds 2 gallons of gasoline mixture. Two of the yards take 1/2 a gallon of gasoline mixture each, a third takes 1/4 gallon, and a fourth takes 1/8 of a gallon. Can he mow all 4 yards on one tank of gasoline mixture? If he can, how much gasoline mixture will be left? If not, how much more will he need?
