Percents
.25 as a percent
25%
Multiply by 100
If you need $100 and you have $80, how much more do you need?
$20
100-80
If it takes you 1/5 of an hour to make 1/4 of a bracelet, how many bracelets can you complete in one hour?
1.25 bracelets or 1 and 1/4 of a bracelet
h .2 1 h
=
b .25 ? b
-12(-3)
36
calculator - use negatives correctly
numbers next to each other with parentheses means to multiply
What is the Constant of Proportionality (k)?
Bags Chips Cost
3 $2.25
4 $3.00
6 $4.50
.75 or 3/4
k = y/x
If you put $1,500 in the bank and you have simple interest of 2%. How much is the interest after 2 years? (I=Prt)
A. $60 B. $30 C. $15
A. $60
I = 1500(.02)2
If the temperature is 3 degrees and it decrease by 2 degrees every 5 minutes, what is the temperature in 10 minutes?
A. 3-2-2 = -1 B. 3-2-2-2=-3
A. 3-2-2 = -1
I can knit 5 1/2 scarves in 3 days, how many scarves can I knit in 1 day?
1.83 or 1 83/100 scarves
s 5.5 ? s
=
d 3 1 d
1/4 of the toys are wood. There are 64 toys. How many are wood?
a. 256 b. 16 c. 63.75
b. 16 wooden toys
.25 OF 64
.25 TIMES 64
What equation matches the table?
A. y=.75x B. x=3/4y
Bags Chips Cost
3 $2.25
4 $3.00
6 $4.50
A. y = .75x
Equation is in the form y=kx
A bike is $75 now and it was $50 last week. What is the percent of increase? |(Original-New)/Original | x 100
A. 25% B. 75% C 50%
C 50%
|50-75| = |-25| / 50= .5 * 100
Subtract 16 from -8
-24
Subtract "FROM" means the "FROM" has to come first. So the -8 comes first. -8-16
A triangle has the following sides:
(3x + 1/7) (2x + 2/7) (x + 1/7)
What is the perimeter?
6x + 4/7
3x + 2x + x = 6x
1/7 + 2/7 + 1/7 = 4/7
What is the product of -1/4 and -2/6?
a. 2/24 b. -2/24 c. 1/3
a. 2/24
PRODUCT means to multiply
-1 X -2 = 2
-4 x -6 = 24
What is the Constant of Proportionality?
(2, 1.5) (3, 2.25)
.75
every ordered pair has the x value first and the y value second so you do y/x to find the k.
A used car is $5,200 but there is a 25% discount. How much is the discount?
A. 5200 x .25 B. 5200 X 25 C. 5200 x .75
A. 5200 x .25
Add -3 1/6 and -1 5/6
a. -4 4/6 b. -5 1/3 c. -5
c. -5
-3 + -1 = -4
-1/6 + -5/6 = -1
-4 + -1 = -5
Sarah works at a restaurant. She makes $12 per hour and gets a weekly food allowance of $50. What equation shows how much she makes a week?
A. y = 12x + 50 B. 50 = x +12y
A. y=12x + 50
(y) or the amount she makes in a week equals $12 times (x) the number of hours she works plus the $50 allowance
1/5 of the class likes pizza and there are 125 students. How many do not like pizza?
a. 25 b. 4/5 c. 100
a. 100
NOT is 5/5 take away 1/5 or 4/5.
4/5 OF 125 means to multiply
.8x125
What is the value of the missing y coordinate?
(2, 1.5) (4, ?)
3
To find a missing y value, we multiply the X value by the k.
Hershey chocolate bars have a length represented by the letter L. They are making the chocolate bar 15% longer. What equation best represents the new length of the Hershey bar? ( N represents "new longer length" and L represents "current length before change")
A. N = .15L B. N = 1.15L C. N = L + .15
B. N = 1.15L
The ONE in 1.15 represents 100% of the original length.
The .15 in 1.15 represents the 15% added on.
Add -10.5 and -2.8
-13.3
Same signs add and keep the sign.
Sarah works at an expernsive clothing boutique. She wants to make MORE THAN $350 each week. She makes $15 each hour and gets a $75 weekly clothing allowance. Which inequality best represents the situation.
A. 75x + 15y > 350 B. 15x + 75 > 350
B. 15x + 75 > 350
$15 dollar time (x) the number of hours she works in a week plus the $75 allowance has to be greater than $350
Cars over $25,000 have a 15% discount and cars under $25,000 have a 10% discount. Which expressions show the correct operations to find the CORRECT PRICES of the cars?
A. .15c and .10c B. .85c and .90c
B. .85cand .90c
The .15c and the .10c shows the discount amount, not the new price of the car with the discount.
What is the value of the missing x coordinate?
(2, 1.5) (4, 3) ( ?, 9)
12
To find an X value, we divide y by the k.