ACT Strategies: Overview Articles

sustain Definition: (verb) to keep in existence or continue. Petersons.com

Add Word of the Day to your personalized My Yahoo! page: About My Yahoo! and RSS »

Problem Each member of a research group visited either the Virgin Islands or Hawaii... Petersons.com

So What? Math questions involving two equations and two unknowns can usually be combined into one equation with one unknown. Petersons.com

Add SAT* Tip of the Day to your personalized My Yahoo! page: About My Yahoo! and RSS »

Here's the math that you'll need to succeed on your ACT:

Arithmetic:

• Simple addition, subtraction, multiplying, and dividing
• Averages, mean, median, and mode
• Percents, ratios and rates, and some probability
• Knowledge of integer properties such as primes, factors, and multiples

Algebra:

• Simplifying algebraic expressions
• Solving simple algebraic equations
• Factoring of quadratic equations
• Working with simple roots and exponents
• Translating from English to algebra, word problems

Geometry:

• Properties of parallel lines
• Properties of triangles, especially right triangles
• Properties of rectangles, squares, and circles
• Finding the volume and surface area of boxes and cylinders
• Coordinate geometry, including lines and linear equations

Trigonometry will be tested, but will only appear on 4 questions. At least 2 of these can be answered by knowing the definitions of sine, cosine and tangent. So don't worry too much if trig wasn't your best subject.

• Skip harder questions until after you've answered questions you know.

• The questions appear in the order in which you probably covered them in school. So you'll see arithmetic questions first, and trigonometry questions last.

• Know the directions going in to the exam; don't waste exam time reviewing them.

Calculator Use:

• Use a calculator you are comfortable with. Use the same one on test day that you use for your practice.

• You don't need a fancy calculator. A standard four-function one is fine.

Rules for Calculator Use:

• Don't reach for your calculator until you've thought about the question.

• If you need to punch a lot of numbers into your calculator to answer a question, think again; you are going about it the wrong way.

Working Backwards

Rather than setting up and solving an equation to find the right answer, working backwards takes advantage of the fact that all Math Test questions give you the right answer; you just have to work out which one it is. You do this by running the answers through the equation in the question until you find the one that works.

Use working backwards when:

• You are asked to solve an equation (this is especially true when the question is in the form of a word problem).

• The answer choices are numbers.

How to work backwards:

• Step 1: Start with the middle choice. If the one you picked works, then it's correct. Stop working! Otherwise, proceed to Step 2.

• Step 2: Eliminate answers that are too big or too small. (If (C) is too small, everything less than (C) must also be too small, because the choices are arranged in order from smallest to largest. If (C) is too big, then everything greater than (C) must also be too big.)

• Step 3: Run the remaining answers through the question until you find the right one.

Plugging in Numbers

Plugging in Numbers works with the answers, eliminating incorrect ones, and homing in on the right one. It almost always involves less messy algebra, and so it is often a lot easier than using traditional algebra.

Use working backwards when:

• The answers are variables

• You are working with percents, fractions, or ratios, and no actual values are given.

How to plug in numbers:

• Step 1: Pick a simple number to replace the variable. Always use 100 for percent questions.

• Step 2: Plug your chosen number into the equations. The result is your target number.

• Step 3: Plug your chosen number into the answer choices, eliminating those that do not yield your target number.

---