Download Example

Math 10 online work that was due
today at the start of class:
Gateway Homework #1 (turn in
worksheet now, while I take roll)
Section 1.4/1.5 Online Homework
Quiz coming up week after next:
Gateway Quiz Try #1
•
•
•
•
8 questions
Online quiz with paper worksheet
no calculator
Worth 80 points (only your best score of the semester counts)
You have had a number of practice Gateway questions
mixed in with your regular homework assignments, but
you should also take Practice Gateway Quiz 1 before the
next class session:
•
•
•
8 questions on the practice Gateway, same type as on the actual Gateway
You can take the practice Gateway as many times as you want, and only
your best score counts for points.
Additional paper versions of practice Gateways can be picked up in the
open lab from any TA or teacher.
REMEMBER: Gateway study help available every MTWTh
in Room 203 JHSW.
Quiz coming up the class session after Gateway
Quiz 1 on sections 1.2 through 1.8
•
•
•
•
•
15 questions; 50 minute time limit
Taken in class, but via the online course web site
Worth 60 points
1 attempt
No calculators allowed
Practice Quiz 1 should be taken at least 2-3 times before the
quiz day:
•
•
•
•
•
19 questions; 50 minute time limit; can take it anywhere
Worth 10 points
Unlimited attempts, only best score counts
Each time you take it, you will get a different set of questions, so the more
times you take it, the more chances you’ll have of seeing all the types of
questions that might be on the real quiz.
Don’t use a calculator, since you can’t on the real quiz.
REMEMBER: Come to the open lab in 203 if you need help.
M – Th.
Any questions on
today’s homework?
(Sections 1.4/1.5)
Reminder: You should be doing this
homework without using a calculator,
because calculators can’t be used for
Quizzes 1 or 2 or the Gateway Quiz.
Please
CLOSE
YOUR LAPTOPS,
and turn off and put away your
cell phones,
and get out your notetaking materials.
Section 1.6
Subtracting real numbers
• Substitute the opposite of the number being
subtracted
• Then add
• a – b = a + (-b)
Example Subtract the following numbers.
(-5) – 6 – (-3) =
(-5) + (-6) + 3 = -8
Example from homework:
Subtract.
−2 − (−2)
Answer: 0
More on subtracting real numbers:
Example: “Subtract -5 from 8”
Write the 8 FIRST, then subtract -5 FROM the 8.
8 – (-5) = 8 + 5 = 13
Example: “Decrease -8 by 15”
This time you start with -8 and then subtract 15.
-8 – 15 = -23
Example: -6 – (2 - 11)
Do the part in parentheses first : 2 – 11 = -9
Now rewrite the problem as: -6 – (-9)
= -6 + 9 = 3
Note: You may find the number line worksheets handed out at the
last class session useful for completing these kinds of problems.
Example from homework:
Subtract 10 from -5.
Answer: -15
Evaluating algebraic expressions:
Example: Evaluate x – y when x = -5 and y = 4
Plug in -5 in place of the x and 4 in place of y:
-5 – 4 = -9
Example from homework
A commercial jet liner hits an air pocket and drops 259 feet.
After climbing 141 feet, it drops another 147 feet. What is its
overall vertical change?
Answer: -265 feet
Section 1.7
Multiplying or dividing 2 real numbers with same sign:
• Result is a positive number.
• Answer is positive if it’s either a positive times a positive
or a negative times a negative.
Examples:
 6(7)  42
5  3 5
   
6  8  16
 2(3)( 5)( 10)  300
126  (3)  42
5  3
5  8  20
         
6  8
6  3 9
2  2
2  3
           1
3  3
3  2
Multiplying or dividing 2 real numbers with different
signs:
• Result is a negative number
• If multiplying more than two numbers together, count the
number of negative signs: if it’s odd, the answer is
negative, if it’s even, the answer is positive
Examples:
 6  7  42
5  12 
4
    
9  25 
15
 2(3)(5)( 10)  300
5  2  5  15 
25
       
6  15  6  2 
4
2
2 1
2
  3      
3
3 3
9
Example from homework
Multiply.
(−7)(2)(−2)(−3)
Answer: -84
Example from homework
Evaluate.
−32
Answer: -9
Some more rules for multiplying and dividing:
• If b is a real number, 0 · b = b · 0 = 0.
• Multiplicative inverses or reciprocals are
two numbers whose product is 1.
• Quotient of any real number and 0 is
undefined.
3
 undefined
0
• The quotient of 0 and any nonzero real number = 0.
0
0
5
Example from homework
Find the reciprocal or multiplicative inverse.
8
−
11
Answer: -11/8
Example from homework
If 𝑥 = −7 and 𝑦 = −4,
9 − 5𝑥
𝑦+4
Answer: N
evaluate the expression.
If a and b are real numbers, and b  0,
a
a
a


b
b
b
In other words, never write a
final answer with a negative
sign on the bottom.
Example
Simplify the following.
86
14
14
8  3(2)
8  (6)

 


3
 9  2(3)  9  (6)  9  6  3
Today’s homework on 1.6 &
1.7 is due at the start of
the next class period.
Reminder: You should be doing this
homework without using a calculator,
because calculators can’t be used
for Quizzes 1 or 2, Test 1 or the
Gateway Quiz.
You may now
OPEN
your LAPTOPS
and begin working on the
homework assignment.