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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. 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






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






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






4. To convert a mixed number to an improper fraction - multiply the whole number by the denominator - then add the numerator over the same denominator - to convert an improper fraction to a mixed number - divide the denominator into the numerator to get






5. Subtract the smallest from the largest and add 1






6. A rectangle is a four-sided figure with four right angles opposite sides are equal - diagonals are equal; Area of Rectangle = length x width






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






8. Add the exponents and keep the same base






9. To divide fractions - invert the second one and multiply






10. Multiply the exponents






11. Part = Percent x Whole






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






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






14. Probability= Favorable Outcomes/Total Possible Outcomes






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






16. Combine like terms






17. An isosceles triangle has 2 equal sides and the angles opposite the equal sides (base angles) are also equal - an equaliteral is a triangle where all 3 sides are equal - thus the angles are equal - regardless of side length the angle is always 60 deg






18. Parentheses - Exponents -Multiplication and Division(reversible) - Addition and Subtraction (reversible)






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






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






21. To increase: add decimal version of percent to one and times that # to the # you want to increase. Example: increase 40 by 25% Work: 1.25*40=? Answer: 50






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






23. 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






24. 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






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






26. 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






27. The largest factor that two or more numbers have in common.






28. Surface Area = 2lw + 2wh + 2lh






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






30. To combine like terms - keep the variable part unchanged while adding or subtracting the coefficients - Example: 2a+3a=? work: (2+3)a answer: 5a






31. Factor out the perfect squares






32. Volume of a Rectangular Solid = lwh; Volume of a Cube= (L)^3






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






34. pr^2






35. 2pr






36. The whole # left over after division






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






38. 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)






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






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






41. The median is the value that falls in the middle of the set - the mode is the value that appears most often






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






43. To add a positive and negative integer first ignore the signs and find the positive difference between the two integers - attatch the sign of the original with higher absolute value - to subtract negative integers simply change it into an addition pr






44. The absolute value of a number is the distance of the number from zero - since absolute value is distance it is always positive






45. Area of Triangle = 1/2 (base)(height) - the height is the perpendicular distance between the side that's chosen as the base and the opposite vertex






46. An arc is a piece of the circumference. If n is the degree measure of the arc's central angle - then the formula is: Length of an Arc = 1 (n/360) (2pr)






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






48. Integers that have no common factor other than 1 - to determine whether two integers are relative primes break them both down to their prime factorizations






49. 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






50. To predict whether the sum - difference - or product will be even or odd - just take simple numbers such as 1 and 2 and see what happens; there are rules like 'odd times even is odd' - but there's no need to memorize them