Math 115: College Algebra, Fall 2009
Week 3
HOMEWORK #5: Due Tuesday, September
22nd:
Homework is due on my desk before
class begins.
Reading
Assignment:
Read: * Re-read Chapter 2, lessons 1, 2 and 3 in the book to
remind yourself of some of the basic ideas.
Homework
Assignment:
· Please write on the top
right-hand of your homework how long you spent on this homework—writing your
pen-pal letter, reading and solving problems.
· I received an email from a
mother of a 10-year old girl. The email
said: “My daughter’s teacher assigned
her a problem. There must be an easier
solution than the approach I used.
Here’s the problem: In a store,
pencils have one price and pens have another price. Two pencils and three pens cost 78
cents. But three pencils and two pens
cost 72 cents. How much does one pencil
cost? My daughter received a hint “how
much will 5 pens and 5 pencils cost?” I solved it algebraically. Here’s my problem (and question for
you): I can’t believe that this is the
easiest solution. This seems way too
algebraic for 10 year olds. What am I
missing?”
Your task:
Figure out a solution that the 10-year old girl would understand.
· Solve each of the following
problems: (a) using bar diagrams as
we did in class (b) using algebra.
1. A total of 900 people
visited the zoo on Friday, Saturday and Sunday.
On Friday, there were 480 visitors.
The number of visitors on Saturday was 180 less than the number of visitors
on Sunday. How many visitors were there
on Sunday?
2. Karen had $47. After paying
for 3 dolls, she had $20 left. Find the
cost of each doll.
3. Caitlyn and Kristin
collected a total of 160 acorns. Kristin
collected 3 times as many acorns as Caitlyn.
How many acorns did Caitlyn collect?
4. Emma used 880g of a packet
of sugar to bake a cake and 1/10 of the remaining sugar to make jelly. She then had 3/7 of the packet of sugar
left. How much sugar was in the packet
at first?
5. Four toy cars cost as much
as 3 dolls. Five toy cars cost $3.50 more than 2 dolls. Diana spent $14 on
equal number of toy cars and dolls. How many toy cars did she buy?
· Please attend the Fresh San
Diego sessions you agreed to attend and be ready to tell us about them. The ones coming up:
1.
Monday, September 21st,
2.
Tuesday, September 22nd,
3.
Tuesday, September 29th,
4.
Wednesday, September 30th,
5.
Thursday, October 1st,
HOMEWORK #6: Due Thursday, September 24th:
Homework is due on my
desk before class begins.
Reading
Assignment:
No reading assignment
Homework
Assignment:
· Turn in your assignment #5
now that you have had the opportunity to rework the problems.
· Please write on the top
right-hand of your homework how long you spent on this homework—writing your
pen-pal letter, reading and solving problems.
· Try to work out the problem
using bar diagrams now that we have had more practice doing it: I received an
email from a mother of a 10-year old girl.
The email said: “My daughter’s
teacher assigned her a problem. There
must be an easier solution than the approach I used. Here’s the problem: In a store, pencils have one price and pens
have another price. Two pencils and
three pens cost 78 cents. But three pencils
and two pens cost 72 cents. How much
does one pencil cost? My daughter
received a hint “how much will 5 pens and 5 pencils cost?” I solved it
algebraically. Here’s my problem (and
question for you): I can’t believe that
this is the easiest solution. This seems
way too algebraic for 10 year olds. What
am I missing?”
· Solve each of the following
problems: (a) using bar diagrams as
we did in class (b) using algebra.
1.
Kristin and Chloe spent $30 at the mall. When
they came back home, Kristin had no money left while Chloe still had $3. If
Kristin spent twice as much as Chloe, how much money did Kristin spend?
2.
Alex had 480 more oranges than pears. After selling
half of his oranges and half of his pears, he had four times as many oranges as
pears left. Find the number of pears he had at first.
3.
Nico has twice as many cards as Sam. Sam has 20 more
cards than Emma. They have 200 cards altogether. How many cards does Nico have?
· Please attend the Fresh San
Diego sessions you agreed to attend and be ready to tell us about them. Please remind me in class! The ones coming up:
1.
Tuesday, September 29th,
2.
Wednesday, September 30th,
3.
Thursday, October 1st,
Back to Reading and
Homework Assignments Back to Math 115
Comments:
pmyers@sandiego.edu