Number Sense
What is the definition of absolute value? Find |-20|
Absolute value is the distance a number is from 0. |-20| = 20
Combine like terms: -18y + 22y =
= 4y
Determine if the ratios are proportional: 4 : 7 and 16 : 49
No 4*4=16 but 7*4 = 28, not 49
A student is randomly selected from a class of 32 students. There are 20 girls in the class. What is the probability that the selected student is a boy?
32 - 20 = 12
12 / 32 = 6 / 16 = 3/ 8
A right triangle with a base of 9 cm and a height of 16 cm has a height of what?
9 x 16 divided by 2
144/2=72
- (4) - (-13) =
-4 - (-13) = 9
Remember: -(-) = +
-4+13 = = 9
Use the distributive property to simplify the expression: -8( -x + 5 ) =
= 8x - 40
Find the unit rate: 39 meters in 13 seconds
3 meters per second
Find the mean, median, mode, and range of the following values: 17, 7, 11, 13, 2, 12, 7
Mean: 9.9 Median: 11 Mode: 7 Range: 17 - 2 = 15
If two angles sum to 90 degrees, what do we call them?
Complementary Angles
1/6 + 3/12 = ? Notice: Unlike denominators!
= 5/12
Use inverse operations to solve for "x"
-11x + 3 = -30
-11x + 3 = -30
1. Subtract 3 from both sides -11x = -33
2. Divide both sides by -11
3. x = 3
Which is the better unit price? $4.00 for a 16-ounce bag of Doritos or $3.60 for a 12-ounce bag of Cheetos?
4.00/16 = $.25 per ounce for Doritos
3.60/12 = $.30 per ounce for Cheetos.
Doritos are a better deal.
A jukebox has 2 rock CDs, 5 country CDs, 7 R&B CDs, and 6 rap CDs. The jukebox randomly selects a CD to play. What are the odds the jukebox will not choose a rock CD?
2 + 5 + 7 + 6 = 20 CDs total Only 2 are rock, so 18/20 are not rock = 9/10 or 90%
Is it possible for a triangle to have two right angles? Why or why not?
A triangle has three angles that must add up to 180 degrees. Two right angles add up to 180 degrees, which means the third angle would have to equal 0 degrees. This is impossible.
(3/5)(4/9) = ? Remember: Fraction multiplication!
12/45 = 4/15
Solve the following inequality for the variable:
x/2 - 4 > 8
x/2 - 4 > 8
1. Add 4 to both sides x/2 > 12
2. Multiply both sides by 2
3. x > 24
Solve the following proportion:
16 / x = 2 / 3
n / 8 = 3 / 4
x = 24
n = 6
2 friends are playing with a normal 52-card deck of cards. Monica and Rachel each take a card from the deck. Joey's turn is next. What is the probability that Joey will get a 9?
Since Monica and Rachel took a card, 52 - 2 = 50 Four 9's in the deck 4/50 = 2/25 chance Joey gets a 9
The diameter of a music CD is 12 cm. Find the circumference of a CD to the nearest TENTH.
Pi = 3.14
C= pi x diameter
37.7 cm
(2/12) รท (8/3) = Remember: Fraction division K, C, F
6/96 = 1/16
A 7th grader is taking his crush to the movies. He has $40 to spend. They go to the movies in the afternoon, when the tickets are only $8 each. He really wants to buy some snacks, too, which are on special for $5 each. Set up an inequality to depict this scenario, and then explain how many possible snacks he could buy.
2*8 + 5x is less than or equal to 40
1. Subtract 16 from both sides: 5x < 24
2. Divide both sides by 5:
3. x < 4 remainder 4 So, he can buy UP TO 4 snacks.
Find the constant of proportionality: (Remember: k = y/x)
x: 5, 10, 15, 20
y: 12.5, 25, 37.5, 50
k = ?
Answer:
12.5/5, 25/10, 37.5/15, 50/20 =2.5
Chandler and Ross are playing cards. What is the probability that Chandler will get a 5 ?
4/52 = 1/13
If you cut a cylinder vertically at the base, what shape would you create?
What is a rectangle.