Question | Answer |
Perimeter | Distance around a shape or figure.
ADD ALL SIDES. |
Area | Amount of space inside a shape.
Units are Squared (cm2) |
Area of a Circle | A = πr^2
Pi x R(squared)
Pi = 3.14 |
Circumference of a Circle | Distance Around
C= 2πr |
Area of a Square/Rectangle/Parallelogram | A= Bh
A = Base x height |
Area of a Triangle | A= ½ bh or A = bh/2 |
Area of a Trapezoid | A= (base 1+base 2)h / 2 |
Surface Area | Total Area of all the faces of a 3D figure.
Find the area of EACH face and then ADD.
Units are squared (cm2) |
Volume | Amount of space inside a 3D figure.
Units are cubed (cm3) |
Volume of a Rectangular Prism and a Cube | V= lwh
V= Length x width x height |
Volume of a Rectangular Pyramid | V=lwh/3 or V=(1/3)lwh
V= length x width x height / 3 or
V= 1/3 x length x width x height |
Volume of a Triangular Prism | V = lwh/2 or V= (1/2)lwh
V= length x width x height /2 or
V= 1/2 x length x width x height |
Pyramid | 3D figure that is tall in height and comes to a point at the top |
Prism | 3D figure that is long in length |
Cross Section | The inside of a 3D figure. "Cutting/ Slicing"
The cross section will be the same as the base parallel to the cut |
Net | The pattern of a 3D figure.
When you unfold a 3D figure you are left with a net. |
Finding the area of Irregular figures. | 1. Look for familiar shapes
2. Find the area of those shapes
3. TOTAL AREA: Add all the areas AREA OF SHADED: Subtract |
Acute Angle | Less than 90 degrees
Small and cute |
Right Angle | 90 degrees
Forms a corner
Square in the corner |
Obtuse angle | More than 90 degrees but less than 180 degrees |
Straight Angle | 180 degrees
Straight line/ Half circle |
Complementary Angles | Two angles that add up to be 90 degrees
Forms a Corner
Corner/ Complementary start with C |
Supplementary Angles | Two angles that add up to be 180
Forms a straight Line
Supplementary/Straight Line start with S |
Adjacent Angles | Two angles that are side by side
They share a wall
Mrs. Parker's Room & Mrs. Wease's Room |
Vertical Angles | Angles across from each other
They are Equal/ Congruent
Mrs. Harmon's Room and Mrs. Parker's Room |
Angles of a Triangle | <1 + <2 + <3 = 180
The three angles of a triangle add up to be 180 degrees |
Sides of a Triangle | Total of the two small sides should be bigger than the 3rd side.
Two small sides (+) > 3rd side |
Finding the Mean | Average
1. Add all the numbers
2. Divide the total by how many numbers in the data set |
Finding the Median | Middle
1. Order least to greatest
2. Cross off numbers until you find the middle
IF THERE ARE TWO MIDDLE NUMBERS
1. Add the two middle numbers
2. Divide by 2 |
Finding the Mode | Most
The number that shows up the most number of times
Ex: 19, 19, 19, 2, 3, 3, 4 The mode is 19 |
Finding the Range | Difference
1. Order least to greatest
2. Subtract the highest number and the smallest number |
Outlier | A number that "lies outside the data"
Stands out
Example: 100, 99, 98, 97,96, 95,94, 1 Outlier is 1 |
Cluster in a data set | A group of numbers together |
Gap in a data set | A empty space between numbers |
Probability | A ratio that compares the number of possible outcomes to the total outcomes.
possible/total
Example: Probability of rolling a 5 on a dice is 1/6 |
Finding Total Outcomes | How many total outfits can be made with 2 shirts, 3 pairs of pants, 4 pairs of socks, and 2 shoes?
2 x 3 x 4 x 2 = 48 total outcomes |
Adding and Subtracting Decimals | Line up the decimal and place value.
Add or Subtract like normal
Bring the decimal straight down |
Multiplying Decimals | Do not line up decimals.
Multiple like normal
Move decimal in the answer the same # of places in the problem |
Dividing Decimals | No decimal on the outside of house.
If there is a decimal on the outside, move to make a whole number
Move inside decimal the same number of times |
Adding & Subtracting Fractions | You must find a common denominator (bottom)
Only add or subtract the numerators (top). |
Multiplying Fractions | Multiply straight across |
Dividing Fractions | KCF
Keep the first fraction the same
Change the division to multiplication
Flip the second fraction (1/2 = 2/1)
Multiply straight across |
Mixed Number | Fraction with a Whole number
4 1/2 |
Improper Fraction | Fraction with a bigger number on top |
Changing a Mixed Number to an Improper Fraction | 1. Multiply the whole number and the denominator
2. Add the numerator.
3. Answer becomes the new numerator and denominator stays the same.
Ex: 4 1/2 4 x 2 = 8 + 1 = 9 9/2 |
Changing an Improper Fraction to a Mixed Number | 1. How many times will the denominator go into the numerator evenly. This becomes the whole number.
2. The remaining becomes the new numerator, denominator stays the same.
Ex. 37/6 37/6 = 6 whole times (6x6=36) with 1 left over
6 1/6 |
Percent | Number out of 100 |
Changing a Percent to a Decimal | DP Move the decimal TWO times to the LEFT |
Changing a Decimal to a Percent | DP Move the decimal TWO times to the RIGHT |
Decimal to a Fraction | Put the number over the last place value and simplify
Ex: 0.4 = 4/10 0.42= 42/100 0.423 = 423/100 |
Fraction to a Decimal | DIVIDE the top by the bottom. |
Fraction to a Percent | Set up a Proportion
1/2 = x/100
Cross Multiply and divide |
Equivalent Fractions | Are they Equal?
1. Find Cross Products - butterfly :(
2. Turn into Decimals
3. Simplify (Simplest form must be the same) |
Percent Proportions | IS x
OF 100
Set up a Proportion with is over of = to x over 100 |
Percent of Change | Amount of Change (subtract) %
Original Amount 100
1. Find the change
2. Set up proportion
3. Solve for % |
Percent Increase | Original Amount goes UP
Original :200
New: 500 |
Percent Decrease | Original Amount goes DOWN
Original :200
New: 25 |
Simple Interest | I = prt
Interest= Principle x rate x time
Interest = EARNED
Principle= Starting Amount
Rate = % ( Must make a decimal)
Time = ALWAYS in YEARS (5 months = 5/12) |
Integer | Positive & Negative Numbers |
Multiplying Same Sign Integers | Same Signs = POSITIVE
Positive x Positive = Positive
Negative x Negative = Positive |
Dividing Same Sign Integers | Same Signs = POSITIVE
Positive / Positive = Positive
Negative / Negative = Positive |
Multiplying Different Sign Integers | Different Signs = NEGATIVE
Positive x Negative = Negative
Negative x Positive = Negative |
Dividing Different Sign Integers | Different Signs = NEGATIVE
Positive / Negative = Negative
Negative / Positive = Negative |
Adding Same Sign Integers | Sign Stays the same
Positive + Positive = Positive
Negative + Negative = Negative |
Adding Different Sign Integers | 1. Subtract the two numbers
2. Answer will be the same sign as the bigger number |
Subtracting Integers | KCO
Keep the first number the same
Change the sign from subtraction to addition
Opposite of the second number ( -2 = 2 3 = -3)
Then follow the rules for Adding |
Finding Tax or Tip | 1. Percent to decimal
2. Multiply (Decimal & Cost)
3. Add (tax/tip and cost)
Equation: Amount(1.00 + percent as decimal) = Total with tax/tip |
Finding Discount | 1. Percent to decimal
2. Multiply (Decimal & Cost)
3. Subtract (Cost & Savings)
Equation: Amount(1.00 - percent as decimal) = Total with discount |
Solving Two Set Equations | UNDO what is being done to the Variable
Whatever you do to one side you have to do the SAME to the other side.
MAKE A T- CHART
Multiplication and Division undo each other
Adding and Subtracting undo each other *** Always +/- first |
Distributive Property | A(b+c) = A(b) + A(c)
The outside number must be multiplied by ALL the numbers inside the Parenthesis. |
Order of Operations | Please Parenthesis () Always go left to right
Excuse Exponents
My Mulitplication
Dear Division
Aunt Addition
Sally Subtraction |
Solving Inequalitites | 2x + 1 > 12 SOLVE JUST LIKE EQUATION
Make T-Chart, Undo (start with +/-)
REMEMBER:
If you Multiply or Divide by a negative number you have to FLIP SYMBOL |
Graphing Inequalities with symbols < or > | Open Circle |
Graphing Inequalities with symbols ≤ or ≥ | Closed Circle |
Graphing Inequalities | Mouth open to variable x > 1: Shade Right
Mouth open to number x < 1: Shade Left |
Adding Opposites | ALWAYS EQUAL 0
Example -2 and 2 -2 + 2 = 0 |
Unit Rate | Always has a denominator of 1. (per, each, every)
Example: If 5 notebooks are $20 the unit rate is how much 1 notebook costs. $20/5 = $4 per notebook.
REMEMBER: $$ on top |
Finding the Better Buy | Find the unit rate for each option.
Unit rate = denominator of 1.
Which ever has the smallest unit rate is the better buy
Ex: 5 shirts for $20 or 6 shirts for $36
$20/5 = $4/1 $36/6 = $6/1
BETTER BUY |
Constant of Proportionality | Unit Rate must be the same/constant for all the data
When given a table, graph, or points (x,y); find the COP by dividing y and x. (y/x) |
Combining Like Terms | Like terms have the same variable.
Ex: 2x and 3x
When combining like terms only add/subtract the numbers
2x + 3x = 5x
A variable without a number (x) = 1x |
Factoring Expressions | Backwards Distributive Property
1. Find the GCF - Greatest Common Factor
2. GCF goes outside the Parenthesis
Ex: 2x + 6 GCF is 2
2(?)= 2x and 2(?)=6
Answer: 2(x + 3) |
Equilateral Triangle | All sides and all angles are equal |
Isosceles Triangle | Two equal Sides and Two equal Angles |
Scalene Triangle | No equal sides and No equal Angles |
Volume for a Triangular Pyramid | V = 1/6 LWH or V = LWH/6 |