ACT MATH TEST • You are given 60 minutes to answer 60 questions. That’s 60 seconds or less per question. • You should memorize the instructions for the Math Test before you arrive to take the test. (see handout) You don’t want to waste a single second looking at the directions on test day. ACT MATH TEST • All questions are printed in the left half of the page. • The right half of the page is for “your figuring and your drawings.” USE IT! ACT MATH TEST • Five, not four, multiple choice answers. Be careful filling in the bubbles on the answer sheet. • Guess on any question you can’t answer. But, your best bet is always to try to eliminate whatever answer choices you can and then guess. ACT MATH TEST • Try to answer the easier questions first. They should take you less than 60 seconds. ACT MATH TEST • If you skip a question be sure to put a mark by it in your test booklet. It’s often suggested that you go ahead and bubble a “best guess” answer on your answer sheet. This would help keep you in order on the answer sheet and you would have a best guess in case you ran out of time and couldn’t get back to that question. ACT MATH STRATEGIES ACT MATH STRATEGY Draw a picture. o Many of the word problems become much easier when you can draw a picture of the situation. o The visual representation may remind you of properties related to the problem. o Be sure to label your drawing accurately to assist with setting up your computations. o This strategy is especially helpful with geometry problems. • Let’s use this strategy on the following problem. Problem Four points, A, B, C, and D lie on a circle having a circumference of 15 units. B is 2 units counterclockwise from A. C is 5 units clockwise from A. D is 7 units clockwise from A and 8 units counterclockwise from A. What is the order of the points, starting with A and going clockwise around the circle? F. A, B, C, D G. A, B, D, C H. A, C, B, D J. A, C, D, B K. A, D, C, B • Answer is J • Did drawing a picture work for you? • Did anyone use a different method to solve this problem? ACT MATH STRATEGY Eliminate two or three answer choices. o In many problems, information is provided that will make two or three of the answers impossible to be the correct answer. o Eliminate these answers and then use the additional information to choose between the remaining answer choices. • Let’s use this strategy on the following problem. Problem What is the least common multiple of 70, 60, and 50? F. 60 G. 180 H. 210 J. 2,100 K. 210,000 • Answer is J • Which answers could you immediately eliminate? Why? • • • • Couldn’t be 60 because of 70. Couldn’t be 180 – not divisible by 50 evenly. Couldn’t be 210 – not divisible by 50 or 60 evenly. 210,000 is a multiple of all 3 numbers but it is not the least common multiple. ACT MATH STRATEGY Substitute numbers for variables. o Many problems are particularly confusing because they only contain variable expressions and few, if any, numbers. o Numbers can be substituted in for the variables to provide more information about the answer to the problem. • Let’s use this strategy on the following problem. Problem The length of a rectangle is 3 times the length of a smaller rectangle. The 2 rectangles have the same width. The area of the smaller rectangle is A square units. The area of the larger rectangle is kA square units. Which of the following is the value of k? F. G. H. J. K. 1/9 1/3 1 3 9 • Answer is J • How did you solve this problem? Did you substitute a number? Draw a picture? • Assume area of rectangle A is 1. Width and height would each be 1 (area=w*h). Width is the same on both rectangles so could determine length of larger rectangle as 3 times the length of smaller or in this case (3)(1). • Picture would be an easy representation. ACT MATH STRATEGY Substitute answers into the problem. o Start with an answer in the middle of the choices. Substitute it into the problem. o If that answer doesn’t work, try to decide if you can eliminate the higher or lower answers. (The numbers are usually listed in numerical order.) o Continue substituting each of the remaining answers until the correct answer is found. • Let’s use this strategy on the following problem. Problem For 2 consecutive integers, the result of adding the smaller integer and triple the larger integer is 79. What are the 2 integers? A. 18, 19 B. 19, 20 C. 20, 21 D. 26, 27 E. 39, 40 • Answer is B • Did you solve this problem by substituting in the pairs? • Did you start with the pair in the middle thereby able to eliminate higher or lower? • Did you solve another way? – Maybe you realized quickly that 3 times 20 in answer B would give you 60 + the 19 would then give you 79 ACT MATH STRATEGY Determine what the question is asking. o Word problems often contain many pieces of information that could be confusing. o It is necessary to read the problem carefully to determine exactly what information the problem is asking you to find. • Let’s use this strategy on the following problem. Problem Lines p and n lie in the standard (x,y) coordinate plane. An equation for line p is y = 0.12x + 3,000. The slope of line n is 0.1 greater than the slope of line p. What is the slope of line n? F. 000.012 G. 000.02 H. 000.22 J. 001.2 K. 300 • Answer is H • What is the question asking? • Do you know what the slope of line p is? (0.12) • Do you know what the slope of line n is? (0.1 > than slope of line p) (0.12 + 0.1…0.22) • Remember…Strategies are just that. • They do not replace math skills. • They are meant to support your understanding of math. • Good strategies can help you put your knowledge of math and the ACT format to the best possible use and help you achieve your target score. • Let’s try a few more problems. Problem Kaya ran 1-2/5 miles on Monday and 2-1/3 miles on Tuesday. What was the total distance, in miles, Kaya ran during those 2 days? A. 3-2/15 B. 3-3/8 C. 3-2/5 D. 3-7/15 E. 3-11/15 • Answer is E • Total distance = sum of 1-2/5 and 2-1/3 • To add mixed numbers, each fraction must have a common denominator • 3 and 5 do not have any common factors other than 1 so the least common denominator is 3(5), or 15 • To convert 2/5, multiply by 3/3 = 6/15 • To convert 1/3, multiply by 5/5 = 5/15 • 1-6/15 + 2-5/15 = 1+2 and 6/15+5/15 = 3-11/15 Problem (3x3)(2x2y)(4x2y) is equivalent to: F. 9x7y2 G. 9x12y2 H. 24x7y2 J. 24x12y K. 24x12y2 • Answer is H • Multiply the constants (3)(2)(4) • When have common base, use the base and add the exponents. • Combine the x terms (x3x2x2 – x3+2+2 – x7) • Combine the y terms (yy – y1y1 – y1+1 – y2) • Result is 24x7y2 If you didn’t get the correct answer, do you see where you made your mistake? Problem If a rectangle measures 54 meters by 72 meters, what is the length, in meters, of the diagonal of the rectangle? F. 48 G. 63 H. 90 J. 126 K. 252 • Answer is H • Did you draw a picture? • Could use the Pythagorean theorem because the sides of the rectangle are the legs of a right triangle • Diagonal of the rectangle is the hypotenuse of the right triangle 72 meters 2 2 2 • Then h = 72 + 54 then h = 80 h 54 meters Problem If a = b + 2, then (b – a)4 = ? F. -16 G. -8 H. 1 J. 8 K. 16 • Answer is K • To find (b - a)4 given a = b+2, you could solve the equation for b - a. • Subtract a and 2 from both sides • You get -2 = b – a • Substitute -2 for b – a in (b – a)4 • (-2)4 or 16 Problem Points B and C lie on AD as shown below. The length of AD is 30 units; AC is 16 units long; and BD is 20 units long. How many units long, if it can be determined, is BC? F. 4 G. 6 A C B H. 10 J. 14 K. cannot be determined from the given information D • Answer is G • Did you use the line drawing to determine your answer? • If AD is 30 units and BD is 20 units then AB is 10 units • If AC is 16 units then AC – AB is 6 units Problem A cord 24 inches long is 5 inches from the center of a circle, as shown below. What is the radius of the circle, to the nearest tenth of an inch? A. 29.0 B. 24.5 C. 16.9 D. 13.0 E. 10.9 r 5 24 • Answer is D • Use the right triangle shown on the diagram • Half the length of the cord is 12 inches (the length of one leg) • The other leg is 5 inches long • The hypotenuse is r inches long • This is a right triangle because the distance between a point and line must be measured perpendicular to the line. • Pythagorean theorem r2 = 122 + 52 then r2 = 169 • r = 13 inches Problem The larger of two numbers exceeds twice the smaller number by 8. The sum of twice the larger and 3 times the smaller number is 65. If x is the smaller number, which equation below determines the correct value of x? F. 3(2x + 8) + 2x = 65 G. 3(2x - 8) + 2x = 65 H. (4x + 8) + 3x = 65 J. 2(2x + 8) + 3x = 65 K. 2(2x - 8) + 3x = 65 • Answer is J • One strategy is to find equations. • In the first part of the problem let y be the larger number and get the equation y = 2x + 8. • The second part of the problem says 2y + 3x = 65. • Substitute 2x + 8 for y in the second equation. • 2(2x + 8) + 3x = 65 To get better at taking the test… – TAKE PRACTICE TESTS – TAKE PRACTICE TESTS – TAKE PRACTICE TESTS Resources • ACT website • http://www.actstudent.org/ • Louisville Free Public Library • http://www.lfpl.org/MyLibraryU/act.htm • The Real ACT Prep Guide • SparkNotes • http://www.sparknotes.com/testprep/act/