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SAT Math: Concepts And Tricks

Subjects : sat, math
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. The largest factor that two or more numbers have in common.






2. 1. Re-express them with common denominators 2. Convert them to decimals






3. To multiply fractions - multiply the numerators and multiply the denominators






4. To solve an inequality do whatever is necessary to both sides to isolate the variable. When you multiply or divide both sides by a negative number you must reverse the sign






5. Factor out the perfect squares






6. Use the sum - Example: if the average of 4 #s is 7 - and the #s are 3 - 5 - 8 - and ____ - what is the fourth #? Work: sum= 4*7 =28 3+5+8=16 28-16=? Answer: 12






7. Expressed A?B (' A union B ') - is the set of all members contained in either A or B or both.






8. To find the reciprocal of a fraction switch the numerator and the denominator






9. Growth pattern in which the individuals in a population reproduce at a constant rate; j-curve graph-- logarithmic - FORMULA: y=a(1+r)^ EXPLANATION: a = initial amount before measuring growth/decay r = growth/decay rate (often a percent) x = number of






10. The intersection of the sets of A and B - written AnB - is the set of elements that are in both A and B.






11. A square is a rectangle with four equal sides; Area of Square = side*side






12. A parallelogram has two pairs of parallel sides - opposite sides are equal - opposite angles are equal - consecutive angles add up to 180 degrees; Area of Parallelogram = base x height






13. To evaluate an algebraic expression - plug in the given values for the unknowns and calculate according to PEMDAS






14. The sum of the measures of the interior angles of a polygon = (n - 2) × 180 - where n is the number of sides






15. To find the prime factorization of an integer just keep breaking it up into factors until all the factors are prime






16. Divisible by 2 if: last digit is even - divisible by 4 if: last two digits form a multiple of 4






17. This is the key to solving most fraction and percent word problems. Part is usually associated with the word is/are and whole is associated with the word of. Example: 'half of the boys are blonds' whole: all of the boys part: blonds






18. Integers are whole numbers; they include negtavie whole numbers and zero - Rational numbers can be expressed as a ratio of two integers - irration numbers are real numbers that cant be expressed precisely as a fraction or decimal.






19. Volume of a Cylinder = pr^2h






20. Multiply the exponents






21. Average the smallest and largest numbers Example: What is the average of integers 13 through 77? Work: (13+77)/2 Answer: 45






22. A sector is a piece of the area of a circle. If n is the degree measure of the sector's central angle then the formula is: Area of a Sector = (n/360) (pr^2)






23. Factor can be divisible (factor of 12 and 8 is 4). Multiple is a multiple (multiple of 12 and 8 is 24).






24. Similar triangles have the same shape: corresponding angles are equal and corresponding sides are proportional






25. When two lines intersect - adjacent angles (angles next to each other) are supplementary (=180) and vertical angles are equal






26. To multiply or divide integers - firstly ignore the sign and compute the problem - given 2 negatives make a positive - 2 positives make a positive - and one negative - and one positive make a negative attach the correct sign






27. To add or subtract fraction - first find a common denominator - then add or subtract the numerators






28. The smallest multiple (other than zero) that two or more numbers have in common.






29. Average A per B: (total A)/(total B) - Example: average speed formula - total distance/ total time - Basically: Don't just average the 2 speeds






30. (average of the x coordinates - average of the y coordinates)






31. To find the y-intercept: put the equation into slope-intercept form (b is the y-intercept): y=mx+b or plug x=0 and solve for y - To find the x-intercept: plug y=0 and solve for x






32. Add the exponents and keep the same base






33. Divisible by 3 if: sum of it's digits is divisible by 3 - divisible by 9 if: sum of digits is divisible by 9






34. 2pr






35. Part = Percent x Whole






36. When a line is tangent to a circle the radius of the circles perpendicular to the line at the point of contact






37. Multiplying: multiply the #s inside the root - but KEEP the ROOT sign - dividing: divide the #s inside the root - but KEEP the ROOT sign






38. Change in y/ change in x rise/run






39. Combine equations in such a way that one of the variables cancel out






40. All acute angles are = all obtuse angles are = any obtuse angle+any acute angle= 180






41. you can add/subtract when the part under the radical is the same






42. To solve a proportion - cross multiply






43. If there are m ways one event can happen and n ways a second event can happen - then there are m × n ways for the 2 events to happen






44. The whole # left over after division






45. Sum=(Average) x (Number of Terms)






46. The 3 angles of any triangle add up to 180 degrees - an exterior angles of a triangle is equal to the sum of the remote interior angles - the 3 exterior angles add up to 360 degrees






47. To find the slope of a line from an equation - put the equation into slope-intercept form (m is the slope): y=mx+b






48. Add up numbers and divide by the number of numbers - Average=(sum of terms)/(# of terms)






49. Probability= Favorable Outcomes/Total Possible Outcomes






50. To reduce a fraction to lowest terms - factor out and cancel all factors the numerator and denominator have in common