Everything to Remember from 7 th Grade Math Order of Operations Description: The order in which addition, subtraction, multiplication, and division are performed determines the answer. Order: 1. Parenthesis: Any operations contained in parentheses are done first, if there are any. 2. Exponents: Exponent expressions are simplified second, if there are any. 3. Multiplication and Division: These operations are done next in the order in which they are found going left to right . 4. Addition and Subtraction: These operations are done next in the order in which they are found going left to right . Example: Place Value Absolute Value Definition: The absolute value of a number is its positive distance from zero. Examples: Decimal Operations ADDITION: - Write the decimal numbers in a vertical form with the decimal points lined up . Example: SUBTRACTION: - Write the decimal numbers in a vertical form with the decimal points lined up . - Write additional zeros after the last digit behind the decimal points (if needed) so the two numbers have an equal number of digits behind the decimal point. Example: MULTIPLICATION: - Multiply as you would regularly (ignore the decimal points). - Count the number of digits behind the decimal point in the answer. The answer must have the same number of digits after the decimal point as there are digits behind the decimal points in all the factors . Example: DIVISION: - Always divide by a whole number . - If the divisor is a whole number, bring the decimal point straight up and divide normally. - If the divisor is a decimal number, multiply both the divisor and dividend by a power of ten (10, 100, 1000…) to make the divisor a whole number. Then divide as above. Integer Operations ADDITION: - If the signs of the numbers are the same , ADD. - The answer has the same sign as the numbers Examples: - If the signs of the numbers are different , SUBTRACT. - The answer takes the sign of the “bigger” (abs value) number Example: SUBTRACTION: - To subtract a number, add its opposite - Meaning… Change the subtraction sign to addition and also change the sign of the number directly behind the subtraction sign to the opposite of whatever it is. Then follow addition rules above. - Remember… Leave, Change, Opposite Example: MULTIPLICATION and DIVISION: - Multiply or divide as normal, then follow these rules to determine the sign of your answer. 1. If the numbers have the same signs , the