Strategy & Math

Timing Chart for PS and BS

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Timing Chart for VR

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Multiplying variable by what fraction is equivalent to: 1) 33% increase, 2) 100% increase, 3)120% increase, 4) 233% increase, 5) 20% decrease, 6) 80% decrease

1) *4/3 2) *2 3) *11/5 4) *10/3 5)*4/5 6)*1/5

Two variables on opposite sides of the equation & on the same side of the division line:

DIRECTLY RELATED

Two variables on same side of the equation & different side of the division line:

DIRECTLY RELATED

If variable manipulating has exponent or root but other doesn't. i.e:. what will happen to distance traveled if time is tripled?

Do the described math to the factor by which you are manipulating it. The result will be the factor by which the OTHER variable (one trying to predict) will change. X=½at²: 3²=9 →9X

Two variables on opposite side of the equation & different sides of the division line:

INVERSELY RELATED

Two variables on same side of the equation & same side of the division line:

INVERSELY RELATED

Log₁₀

Log₁₀ x = n; 10ⁿ = x

Scientific Notation

Mantissa (i.e., 2.0) Power or Exponent (i.e., × 10⁴) Add/Subtract: Multiply/Divide: Raise to the Power: Take the square/other root: LARS (Left Add, Right Subtract) moving decimel 0.05×10⁻² → 5.0E-4 220×10¹² → 2.20E14

Estimating Fractions:

Numerator is larger: create compound fraction (13/5 → 2&3/5) = 2.60 Denominator is larger: "high low method": change denominator to one higher and one lower. Usually will yield one familiar fraction. (7/13→7/12 & 7/14), little more than 0.5)

MCAT Structure

Physical Sciences: Physics and General Chemistry 52 questions / 70 minutes Verbal Reasoning: 40 questions / 60 minutes Biological Sciences: Biology and Organic Chemistry 52 questions / 70 minutes

Linear vs. Non-Linear Graphs

Two variables in an equation, and one or both contains an exponent, the graph of either variable vs. the other will yield a non-linear graph. Examples: X = ½at²: X vs. t, t vs. X, a vs. t & t vs. a (non-linear) X vs. a, or a vs. X (linear) v=√(2gh): v vs. g (non-linear) g vs. h (linear) -both under square root

SI Units & Prefixes

deci- 10⁻¹ deca- 10¹ centi- 10⁻² hecto- 10² milli- 10⁻³ kilo- 10³ micro- 10⁻⁶ mega- 10⁶ nano- 10⁻⁹ giga- 10⁹ pico- 10⁻¹² tera- 10¹² femto- 10⁻¹⁵

Timing Rules

#1: On all sections, (PS/VR/BS) spend a total of 8 minutes per passage. #2: 4 min per Stand-alone. Spaced within the passages and after the last passage. Total of 13 stand alone questions divided into groups of 3-5 questions each. The authors tend to include only 3 questions per set when they are more time consuming and five per set when they are less time consuming. #3: Of the 8 minutes spent on BS/PS, spend 1-2 minutes reading the passage and the rest of time answering questions. On verbal, spend 4-5 minutes reading the passage and developing a main idea;the rest of time answering the questions. #4: Before you begin the exam, write out the timing on your scratch paper. Do this during the "tutorial time," #5: Do NOT go over your time limit on any question, period. On all PS/BS passages you will have one full minute per question and two minutes to read the passage. On verbal passages you will have 4-5 minutes to read the passage and develop your main idea and approximately 45 seconds per question. You MUST finish all sections on time to score well.

Recognizing when to manipulate equations:

1) If X doubles, what happens to Y 2) Two trials, some variable changed by specific factor 3) Data Charts: multiple trials 4) Half in passage/ half in question 5) What is the ratio between A&B, take info from one trial and manipulate equations to determine value for second trial, then take answers and determine ratio.

Manipulating equations using PERCENTAGES: 1) if something goes down by 20%, by what factor is it changed? 2) if something goes down by 25%?

1) it has been multiplied by a factor of 4/5, if the OTHER factor is directly related, it will be multiplied by 4/5, if other is inversely related multiplied by 5/4. 2) same as above but multiplied by 3/4

2 Caveats for Manipulating Equations

1) only works for ×/÷ not if +/- in equation 2) only works if the 2 variables considered are the only ones changing and all other variables in equation remain constant. *can assume that all other variables remain constant on MCAT

How to Answer MCAT Questions

1. Read entire question carefully 2. Rephrase question stem in own words 3. Read and consider A thru D, individually 4. As consider each answer, rephrase with question stem. 5. If answer is wrong "probably not", if correct "maybe" 6. Extremely careful with "NOT, EXCEPT, LEAST, WEAKENS, STRENGTHENS" 7. Use Socratic Method 8. If stuck - try to recognize simple concept, write out everything you know about it.

Estimating decimals from fractions: 1/2, 1/3, 1/4, 1/5, 1/6, 1/8, 3/8, 5/8, 6/8, 7/8

1/2 = .5 1/3 = .33 1/4 = .25 1/5 = .2 1/6 = .17 1/8 = .125 3/8 = .375 5/8 = .625 6/8 = .75 7/8 = .875

Area & Circumference of Circle

A=πr² C=2πr

Graph Answer Choices:

Ask yourself: 1) Does the y-value start high or low? 2) What is the Slope 3) What is the sign of the y axis?

If variable manipulating does not have exponent or root but the other variable does. i.e.: what happens to time if the distance is tripled?

Ask yourself: "What factor can I plug into the OTHER variable so after I do the math, it will match the factor by which I am manipulating the first variable." X=½at²: what squared equals 3? = √3

Pythagorean Theorem

A²+B²=C² Sum of angles of Triangle = 180°

Estimating/Rounding

Round EVERYTHING! MCAT answer choices are usually very far apart. In the rare case that the answer choices are fairly close, this is a clue that it is a simple one-step calculation. You can always go back and narrow your calculations if you need to, don't waste precious time.

Trigonometry Review

Sin 0° 30° 45° 60° 90° 0 1/2 √2/2 √3/2 1 Cos 0° 30° 45° 60° 90° 1 √3/2 √2/2 1/2 0 * √2=1.4; √3=1.7; √2/2=.7; √3/2=.9

Estimating Square Roots: *square of all numbers 1-15 *whats the square root of 72?

find one square root just above and just below the number you are taking the square root of. Answer will be between those two. 8²=64 & 9²=81, between 8 & 9 =~ 8.5

Manipulating equations using FRACTIONS: *what happens to distance traveled if time increases by a factor of 3/2?

remember 3/2 is the factor, the variable being manipulated has a square on it. Do the math top and bottom. The factor by which the OTHER variable with change is 9/4

Degrees → Radians

π radians=180°, 2π radians=360° *π=3 for MCAT; 1 circle (360°) = ~6 rad