Definitions, Key Points, Strategies

  1. Integer:
    Any whole # (pos or neg). Not a fraction or decimal
  2. Divisor/Factor:
    Pos integer that can divide into another integer

    ex: 3 & 4 (factors/divisors) of 12
  3. Prime #:
    An integer divsible ONLY by itself & 1
  4. Dividend:
    The # being divided (N)

    • D same D÷N same N/---D
    • N
  5. Divisor:
    The # dividing into the dividend (D)

    • D same D÷N same N/---D
    • N
  6. Real #:
    Any # (not Sq. root of a neg variable)
  7. Rational #:
    Finite set of decimals ex. 3.5, 2, -5
  8. Irrational #:
    Infinite set of decimals ex. 0.3333...
  9. What # is a multiple of all integers?
  10. Can Factors be pos, neg, or both?
    No, only positive
  11. What # is a factor of all integers?
  12. If a # has ONLY two factors it is a ...
    Prime #
  13. Hint for Division:
    Think of division as multiplication and the key is finding zeroes - so use multiples of 10 or 100
  14. Strategies for Problem Solving:
    1) Read the problem carefully to understand the question. Also note if a figure is drawn to scale or not.
    2) Review answer choices before starting to solve
    3) Look for a shortcut if there is one. Use it if it takes less time than just solving.
    4) Execute approach & watch for careless errors
    5) Before selecting answer, re-read question to make sure your answer is what they were asking for.
    6) If your answer doesn't match answer choices, go back & check for careless errors or approach problems. Perhaps backsolve from answer choices.
  15. If you try to backsolve on word problems (although rarely effective), you should start with answer choice C.
  16. When should you consider "Picking your own #s" on Problem Solving questions?
    • 1) When answer choices consist of variables, percentages, or ratios only. No #s
    • 2) Great when a percentage problem. Use 100
  17. What are the two strategy options for a majority of mixture problems (questions in which you are asked to make some calculation relating to different solutions/groups)?
    1) Use the weighted avg. and ratio to total (tug of war)

    2) Create two algebraic equations with two unknowns and solve for the unknowns.
  18. If a mixture problem has variables in the answers, what's the strategy to solve?
    Solve Algebraically and create 1 equation (where one side equals the other), then isolate for variable answer.
  19. Semiannual vs. Biannual means what?
    Semiannual means twice a year. Biannual means every other year.
  20. What's the difference b/w simple & compunded interest?
    Simple is the interest calculated on the orig. principle only. Compounded is calculated on the principle AND any interest already accumulated during a set period.
  21. What is the formula for compound interest?
    b (1+i)n

    • b= beginning principle
    • i = interest rate (for 1 period)
    • n = number of periods
  22. What is the formula for simple interest?
    b (1 + i * n)

    • b= beginning principle
    • i = interest rate (for 1 period)
    • n = number of periods
Card Set
Definitions, Key Points, Strategies
Math Definitions & Key Points