Cheatography

# STATS & MATH Prep Cheat Sheet (DRAFT) by Ktroch

From basic arithmetic to Expressions and Polynomials. BEDMAS - Squared Numbers - Square Roots - Integers

This is a draft cheat sheet. It is a work in progress and is not finished yet.

### BEDMAS

 • Brackets • Exponents • Division • Multip­lic­ation • Addition •Subtr­action
Brackets Operations within brackets should be done first if there is two sets of brackets, solve the inside brackets then the outside.
Exponents refer to squared numbers and squared roots - A number that amplifies another number Ex: 3³ OR ∛

### Place Value

 Tens Ones. Tenths Hundredths Thousa­ndths Ten Thousa­ndths Hundred Thousa­ndths

### Calculator keys

 Squared x2 Exponent xx Negative ( - ) or +/- square Root √◻ Root shift + x◻ Fractions - ▬/◻ Brackets ( OR )
Buttons will vary depending on your calculator

### Squared Numbers and Square Roots

 Squared Numbers - Multip­lying a number by itself Square Roots - Determ­ining which number multiplied by itself equals the number under the square root sign.

### Fractions: Part of a whole.

 Numerator is the top number Denomi­nator is the bottom Multip­lying Fractions multiply the numerators and then multiply the denomi­nators , then simplify Dividing invert the second fraction and multiply. Adding­/Su­btr­acting Fractions If the denomi­nator is the same , add or subtract the numera­tors. If the denomi­nator is different then find the least common multiple between the denomi­nators and use that for the denomi­nator. Multiply both numerator and denomi­nator by the value needed to obtain the common denomi­nator.
Denomi­nator is how many there are as a whole. Numerator is how many there are FROM the denomi­nator.

### Probab­ility

 Certain 1:1, 100%, 1, 1/1 chance Likely 0% and 100% Unlikely 0 to 1 Impossible 0:1, 0%, 0, 0/1 chance
Formal probab­ility rule:
All range between 0 and 1 (or 0% and 100%) always

### Statistics

 Statistics To help find patterns and relati­onships in data. Data Inform­ation with context Quanti­tative Variable Results in numbers with units where taking an average makes sense. Charts, graphs, plots spread = smallest value to biggest value Categorial Variables Results in inform­ation placed into groups or catego­ries. ( the count ∻ the total * 100 = the %

### Integers

 Integers- are whole numbers (not decimals) positive, negative, or zero Example: 4 , -7 , 0 Integers on a number line The larger the number, positive or negative the further it is away from zero. Absolute value of a number: is the distance away from zero. To represent the absolute value of a number, you write it like this |5| AddingWhen you are adding Positive integers you move right on the number line. 3 + 4 = 7 ⇒ 3 →→→→ 7 When adding Negative numbers , you move to the left on the number line* 5+(-2) = 3 ⇒ 3←← 5 Subtra­cting Subtra­ction is opposite of addition. Subtract a positive number count to the left. Subtract a negative number and count to the right. Multip­lying & Divinding 2 positive integers = A positive 2 negative integers = A positive. 2 integers with mixed signs = A negative.

### Propor­tions and Ratios

 Ratio: A way to describe the relati­onship between two numbers. 2:1 OR 2 to 1 Propor­tions A way to describe the relati­onship between two numbers using a ratio or decimal. Equivalent Ratios Look different but equal the same. 3:6=0.5 4/8 =0.5

### Scientific notation

 230000­000.00 = 2.3 x 108 .000000012 = 1.2 x 10-8
Scientific notation is a way of writing really big or really small numbers Using the base number 10. When doing a small number the exponent is negative

### Scientific notation

 230000­000.00 = 2.3 x 108 .000000012 = 1.2 x 10-8
Scientific notation is a way of writing really big or really small numbers Using the base number 10. When doing a small number the exponent is negative

### Calculator

Use this question to see if your calculator follows the order of operat­ions.
25 - 3x6 = ?
If the answer 7, then it DOES follow the order of operat­ions.
If the answer 132, then it does NOT.

### Decimals

 Decimals are like fractions, they are part of a whole. To turn a fraction into a decimal, divide the numerator by the denomi­nator. To turn a decimal in to a fraction, place the decimal over its place value and then simplify. (find the common denomi­nator with factor­ing.) Decimal Rounding : How many decimal points do you want to keep? Look at the number to the right of the value. If the number is less than 5 keep it and drop the rest to the right. If the number is greater than or equal to 5 then add 1 to the number and drop the remaining to the right.

### Algebra Terms

 Letters are used to represent missing numbers in an equation. Constants Are the numbers in the equation. Variables Are the letters in the equation. Coeffi­cient A number that is directly followed by a variable. Grouped like this we are to multiply

### Mean and Median

 Mean Mean = Average, Add all values and then divide by the number of values. x or a y with a bar over it. y=∑y/n Median The center, equal amount of units on each side First sort smallest to biggest then use the formula, Odd Median­=Middle value, in position. Even Median­=Av­erage of two middle numbers , average of values in position Odd (n+1/2) Even (n/2) and (n/2+1)