7th grade MATH
Statistics and probabilities
PERCENTS. In mathmatics, a percentage is number or ratio that can be expressed as a fraction of 100.
Rational A rational number is any number that can be written as the ratio of two integers
Ratios. A ratio is an ordered pair of numbers a and b, written a / b where b does not equal 0
Geometry.
The branch of mathematics concerned with the properties and relations of points, lines, surfaces, solids, and higher dimensional analogs.
Expressions, Equations& inequalities. An expression is a mathematical phrase that contains numbers, variables, or both. Expressions never have an equal sign.
Tax.
A compulsory contribution to state revenue, levied by the government on workers' income and business profits, or added to the cost of some goods, services, and transactions.
Commission.
By definition, commission is fee paid to an employee for transacting a piece of business or performing a service.
Mark-up. Add a certain amount to the cost of goods to cover overhead and profit.
Calculating tip.
A tip is typically a percentage of a total cost, and they are given in appreciation of a service.
Mark-down. A mark down is an amount by which you decrease the selling price
Simple interest. Simple interest calculated on the principal portion of a loan or the original contribution to a savings account.
Perimeter.
Perimeter is the distance around the edge of a shape.
Surface area. Surface area is the amount of space covering the outside of a three-dimensional shape. :
Geometry facts.
Geometry is a branch of mathematics that studies the sizes, shapes, positions angles, and dimensions of things.
Integers. A whole number a number that is not a fraction
Fractions
Absolute Value. The magnitude of a real number without regard to its sign.
Adding.
The addition is taking two or more numbers and adding them together
Multiplying. The act or process of multiplying
Subtraction The process or skill of taking one number or amount away from another.
Dividing.
The division is a method of distributing a group of things into equal parts.
Subtraction.
Subtraction is the operation of taking the difference of two numbers
Multiply.
Multiplication is a method of finding the product of two or more numbers.
Add. To bring two or more numbers (or things) together to make a new total.
Divide.
To divide is to perform the operation of division
Equations
In algebra, an equation can be defined as a mathematical statement consisting of an equal symbol between two algebraic expressions that have the same value.
Inequalities
Inequalities are relationships between two expressions which are not equal to one another.
Expressions An expression is a set of terms combined using the operations +, – , x or , for example 4 x − 3 or x 2 – x y + 17 .
Probability. Probability is the chance that something will happen, or how likely it is that an event will occur. When we toss a coin in the air, we use the word probability to refer to how likely it is that the coin will land with the heads side up.
Area.
Area is term used to define the amount of space taken up by a 2D shape or surface.
Proportions
A proportion an equation in which two ratios are set equal to each other.
Example is say you invest $100 (the principal) at a 5% annual rate for one year. The simple interest calculation is: $100 x . 05 interest x 1 year = $5 simple interest earned after one year.
Example Say you and a friend had dinner and the check came to $26.50. You had good service and want to leave an 18% gratuity. Put the percentage in decimal form as 0.18 then multiply the check amount by this number. 26.50 * 0.18 = 4.77.
Example
Some employees earn commission in addition to their base income, while other employees work only on commission. When an employee earns a commission, they make a portion of the sale in income. For example, if an employee sells a couch for $500 and they get a 10% commission on all sales, then they earn $50 on that sale.
Example
Include general and selective sales taxes, value-added taxes (VAT), taxes on any aspect of manufacturing or production, taxes on legal transactions, and customs or import duties.
Example
Markup is the difference between a product's selling price and cost as a percentage of the cost. For example, if a product sells for $125 and costs $100, the additional price increase is ($125 – $100) / $100) x 100 = 25%.
Example
To illustrate, suppose a broker sells shares of XYZ stock to his clients at $20 per share. He originally purchased the shares in the broker market at $40 per share. Therefore, the markdown on the shares he sells is -$20 ($20-$40).
Statistics The practice or science of collecting and analyzing numerical data in large quantities, especially for the purpose of inferring proportions in a whole from those in a representative sample.
Example. weather forecasting
Measures of central. A measure of central tendency is a summary measure that attempts to describe a whole set of data with a single value that represents the middle or centre of its distribution.
Common methods to represent statics. Tables, charts and graphs are all ways of representing data, and they can be used for two broad purposes.
Median. The median is the middle value in a list ordered from smallest to largest.
Example. 1234567. This median is 4.
Bar Graphs
Mode.
The mode is the value that occurs most often.
Mean. In mathematics, a quantity that has a value intermediate between those of the extreme members of some set.
Circle graphs
Scatter plots.
A graph in which the values of two variables are plotted along two axes, the pattern of the resulting points revealing any correlation present.
Example. 10+10+10+10+10=50 50÷5=10
Example. 6,3,4,4,4,4,4,4 This mode is 4.
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