Test your basic knowledge |

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






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






3. Part = Percent x Whole






4. Probability= Favorable Outcomes/Total Possible Outcomes






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






6. 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






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






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






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






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






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






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






13. 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






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






15. If a right triangle's leg-to-leg ratio is 5:12 - or if the leg-to-hypotenuse ratio is 5:13 or 12:13 - it's a 5-12-13 triangle






16. 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)






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






18. Factor out the perfect squares






19. 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






20. 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






21. 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






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






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






24. 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






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






26. Add the exponents and keep the same base






27. Multiply te coefficients and the variables separately Example: 2a*3a Work: (23)(aa) Answer: 6a^2






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






29. 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






30. 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






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






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






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






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






35. 1. turn it into ax^2 + bx + c = 0 form 2. factor 3. set both factors equal to zero 4. you get 2 solutions






36. Domain: all possible values of x for a function range: all possible outputs of a function






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






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






39. Use special triangles - pythagorean theorem - or distance formula: v(x2-x1)²+(y2-y1)²






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






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






42. For all right triangles: a^2+b^2=c^2






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






44. Subtract the smallest from the largest and add 1






45. Example: If the ratio of males to females is 1 to 2 - then what is the ratio of males to people? - work: 1/(1+2) answer: 1/3






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






47. 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






48. 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






49. 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)






50. pr^2